diff --git a/app/__init__.py b/app/__init__.py
index e69b946..2e3152f 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -1,6 +1,8 @@
 # app/__init__.py
 
+import click
 from flask import Flask
+from flask.cli import with_appcontext
 from flask_sqlalchemy import SQLAlchemy
 from flask_migrate import Migrate
 from werkzeug.middleware.proxy_fix import ProxyFix
@@ -11,6 +13,18 @@ import sqlite3
 db = SQLAlchemy()
 migrate = Migrate()
 
+
+# =============================================================================
+# CLI Commands
+# =============================================================================
+
+@click.command("version-check")
+@with_appcontext
+def version_check_command():
+    """Check app version and run data migrations if needed (e.g., phash recomputation)."""
+    from app.utils.version_migration import check_and_run_migrations
+    check_and_run_migrations()
+
 @event.listens_for(Engine, "connect")
 def set_sqlite_pragma(dbapi_connection, connection_record):
     # Only apply to SQLite connections
@@ -38,4 +52,7 @@ def create_app(config_class='config.Config'):
     def datetimeformat(value, format="%Y-%m-%d"):
         return value.strftime(format) if value else ""
 
+    # Register CLI commands
+    app.cli.add_command(version_check_command)
+
     return app
diff --git a/app/main.py b/app/main.py
index ce83867..3a48c0b 100644
--- a/app/main.py
+++ b/app/main.py
@@ -2,8 +2,10 @@
 
 from flask import Blueprint, render_template, flash, redirect, url_for, abort, send_from_directory, request, jsonify
 
-from sqlalchemy import desc, func, text
+from sqlalchemy import desc, func, text, extract
 from sqlalchemy.orm import joinedload
+from collections import OrderedDict
+from datetime import datetime
 
 from app.models import ImageRecord, Tag, ArchiveRecord, image_tags
 from app import db
@@ -78,35 +80,47 @@ def random_images_api():
 @main.route('/gallery')
 def gallery():
     """
-    Gallery with pagination and optional tag filter (?tag=artist:NAME or any tag name).
-    Keeps your pagination shape so modal-pagination.js continues to work.
+    Gallery with infinite scroll and year-month date dividers.
+    Server renders initial batch, then JS takes over for infinite scroll.
+    Optional tag filter via ?tag=artist:NAME or any tag name.
     """
-    page = request.args.get('page', 1, type=int)
-    per_page = request.args.get('per_page', 35, type=int)
+    initial_limit = 30
     tag_name = request.args.get('tag')
 
-    # Base query + eager-load tags (cheap and future-proofs tag chips)
+    # Base query + eager-load tags
     q = ImageRecord.query.options(joinedload(ImageRecord.tags))
 
     # Optional tag filter
     if tag_name:
         q = q.join(ImageRecord.tags).filter(Tag.name == tag_name)
 
-    images = q.order_by(desc(func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at))) \
-              .paginate(page=page, per_page=per_page)
+    # Fetch initial batch ordered by date descending
+    images = q.order_by(
+        desc(func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at))
+    ).limit(initial_limit + 1).all()
 
-    # Preserve next/prev URLs (carry tag= so modal pagination fetches stay filtered)
-    next_url = url_for('main.gallery', page=images.next_num, per_page=per_page, tag=tag_name) if images.has_next else ''
-    prev_url = url_for('main.gallery', page=images.prev_num, per_page=per_page, tag=tag_name) if images.has_prev else ''
+    # Check if there are more images
+    has_more = len(images) > initial_limit
+    if has_more:
+        images = images[:initial_limit]
+
+    # Group by year-month for initial render
+    grouped_images = _group_images_by_month(images)
+
+    # Compute initial cursor for JS to continue from
+    initial_cursor = None
+    if images and has_more:
+        last_img = images[-1]
+        last_dt = _get_image_date(last_img)
+        if last_dt:
+            initial_cursor = last_dt.isoformat()
 
     return render_template(
         'gallery.html',
-        images=images,
+        grouped_images=grouped_images,
         active_tag=tag_name,
-        has_next=images.has_next,
-        next_page_url=next_url,
-        has_prev=images.has_prev,
-        prev_page_url=prev_url
+        initial_cursor=initial_cursor,
+        has_more=has_more
     )
 
 
@@ -115,6 +129,265 @@ def serve_image(filename):
     return send_from_directory('/images', filename)
 
 
+# ----------------------------
+# Gallery Infinite Scroll API
+# ----------------------------
+
+def _get_image_date(img):
+    """Get the effective date for an image (taken_at or imported_at)."""
+    return img.taken_at or img.imported_at
+
+
+def _format_year_month(dt):
+    """Format a datetime as year-month key and label."""
+    if not dt:
+        return 'unknown', 'Unknown Date'
+    return dt.strftime('%Y-%m'), dt.strftime('%B %Y')
+
+
+def _group_images_by_month(images):
+    """
+    Group images by year-month, preserving order.
+    Returns list of (group_info, images) tuples.
+    """
+    groups = OrderedDict()
+
+    for img in images:
+        dt = _get_image_date(img)
+        key, label = _format_year_month(dt)
+
+        if key not in groups:
+            groups[key] = {'key': key, 'label': label, 'images': []}
+
+        groups[key]['images'].append(img)
+
+    return [(info['key'], info['label'], info['images']) for info in groups.values()]
+
+
+def _serialize_image(img):
+    """Serialize an ImageRecord for JSON response."""
+    is_video = img.filename.lower().endswith(('.mp4', '.mov'))
+    thumb_path = (img.thumb_path or img.filepath).replace('/images/', '')
+    full_path = img.filepath.replace('/images/', '')
+    dt = _get_image_date(img)
+    key, label = _format_year_month(dt)
+
+    return {
+        'id': img.id,
+        'filename': img.filename,
+        'thumb_url': url_for('main.serve_image', filename=thumb_path),
+        'full_url': url_for('main.serve_image', filename=full_path),
+        'is_video': is_video,
+        'date': dt.strftime('%Y-%m-%d') if dt else '',
+        'year_month': key,
+        'year_month_label': label,
+        'tags': [{'name': t.name, 'kind': t.kind} for t in img.tags if t.kind != 'archive']
+    }
+
+
+@main.route('/api/gallery/scroll')
+def gallery_scroll():
+    """
+    Cursor-based infinite scroll endpoint with date grouping.
+
+    Query params:
+      - cursor: ISO datetime string for pagination (fetch images older than this)
+      - limit: number of images per batch (default 30)
+      - tag: optional tag filter
+
+    Returns:
+      - images: list of image objects with year_month grouping info
+      - next_cursor: datetime string for next batch (null if no more)
+      - date_groups: summary of year-month groups in this batch
+      - has_more: boolean indicating if more images exist
+    """
+    cursor_str = request.args.get('cursor')
+    limit = request.args.get('limit', 30, type=int)
+    tag_name = request.args.get('tag')
+
+    # Build base query
+    q = ImageRecord.query.options(joinedload(ImageRecord.tags))
+
+    # Optional tag filter
+    if tag_name:
+        q = q.join(ImageRecord.tags).filter(Tag.name == tag_name)
+
+    # Apply cursor filter (fetch images older than cursor)
+    if cursor_str:
+        try:
+            cursor_dt = datetime.fromisoformat(cursor_str.replace('Z', '+00:00'))
+            q = q.filter(
+                func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at) < cursor_dt
+            )
+        except ValueError:
+            pass  # Invalid cursor, ignore
+
+    # Order by date descending and fetch with limit + 1 to check has_more
+    images = q.order_by(
+        desc(func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at))
+    ).limit(limit + 1).all()
+
+    # Check if there are more images
+    has_more = len(images) > limit
+    if has_more:
+        images = images[:limit]
+
+    # Serialize images
+    serialized = [_serialize_image(img) for img in images]
+
+    # Build date_groups summary
+    groups_seen = OrderedDict()
+    for s in serialized:
+        key = s['year_month']
+        if key not in groups_seen:
+            groups_seen[key] = {'key': key, 'label': s['year_month_label'], 'count': 0}
+        groups_seen[key]['count'] += 1
+
+    # Compute next cursor
+    next_cursor = None
+    if images and has_more:
+        last_img = images[-1]
+        last_dt = _get_image_date(last_img)
+        if last_dt:
+            next_cursor = last_dt.isoformat()
+
+    return jsonify(
+        images=serialized,
+        next_cursor=next_cursor,
+        has_more=has_more,
+        date_groups=list(groups_seen.values())
+    )
+
+
+@main.route('/api/gallery/timeline')
+def gallery_timeline():
+    """
+    Returns all year-month groups with counts for timeline navigation.
+
+    Query params:
+      - tag: optional tag filter (same as gallery)
+
+    Returns list of {key, label, count, year} ordered newest to oldest.
+    """
+    tag_name = request.args.get('tag')
+
+    # Use SQL to aggregate by year-month
+    date_expr = func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at)
+
+    q = db.session.query(
+        extract('year', date_expr).label('year'),
+        extract('month', date_expr).label('month'),
+        func.count(ImageRecord.id).label('count')
+    )
+
+    if tag_name:
+        q = q.join(ImageRecord.tags).filter(Tag.name == tag_name)
+
+    q = q.group_by(
+        extract('year', date_expr),
+        extract('month', date_expr)
+    ).order_by(
+        extract('year', date_expr).desc(),
+        extract('month', date_expr).desc()
+    )
+
+    results = q.all()
+
+    # Format results
+    groups = []
+    for row in results:
+        if row.year and row.month:
+            year = int(row.year)
+            month = int(row.month)
+            key = f"{year:04d}-{month:02d}"
+            # Create a date object to format the month name
+            dt = datetime(year, month, 1)
+            label = dt.strftime('%B %Y')
+            short_label = dt.strftime('%b')  # Short month name for sidebar
+            groups.append({
+                'key': key,
+                'label': label,
+                'short_label': short_label,
+                'year': year,
+                'month': month,
+                'count': row.count
+            })
+
+    return jsonify(groups=groups)
+
+
+@main.route('/api/gallery/jump')
+def gallery_jump():
+    """
+    Fetch images starting from a specific year-month for timeline jump navigation.
+
+    Query params:
+      - year_month: target year-month (e.g., '2024-03')
+      - limit: number of images (default 30)
+      - tag: optional tag filter
+
+    Returns same format as /api/gallery/scroll but starting from the target month.
+    """
+    year_month = request.args.get('year_month', '')
+    limit = request.args.get('limit', 30, type=int)
+    tag_name = request.args.get('tag')
+
+    if not year_month:
+        return jsonify(error='year_month is required'), 400
+
+    try:
+        # Parse year-month to get start of that month
+        target_dt = datetime.strptime(year_month + '-01', '%Y-%m-%d')
+        # Get end of month (start of next month)
+        if target_dt.month == 12:
+            next_month = datetime(target_dt.year + 1, 1, 1)
+        else:
+            next_month = datetime(target_dt.year, target_dt.month + 1, 1)
+    except ValueError:
+        return jsonify(error='Invalid year_month format'), 400
+
+    # Build query for images in that month and earlier
+    q = ImageRecord.query.options(joinedload(ImageRecord.tags))
+
+    if tag_name:
+        q = q.join(ImageRecord.tags).filter(Tag.name == tag_name)
+
+    # Get images from start of target month onwards (but ordered descending)
+    date_expr = func.coalesce(ImageRecord.taken_at, ImageRecord.imported_at)
+    q = q.filter(date_expr < next_month)
+
+    images = q.order_by(desc(date_expr)).limit(limit + 1).all()
+
+    has_more = len(images) > limit
+    if has_more:
+        images = images[:limit]
+
+    serialized = [_serialize_image(img) for img in images]
+
+    # Build date_groups summary
+    groups_seen = OrderedDict()
+    for s in serialized:
+        key = s['year_month']
+        if key not in groups_seen:
+            groups_seen[key] = {'key': key, 'label': s['year_month_label'], 'count': 0}
+        groups_seen[key]['count'] += 1
+
+    next_cursor = None
+    if images and has_more:
+        last_img = images[-1]
+        last_dt = _get_image_date(last_img)
+        if last_dt:
+            next_cursor = last_dt.isoformat()
+
+    return jsonify(
+        images=serialized,
+        next_cursor=next_cursor,
+        has_more=has_more,
+        date_groups=list(groups_seen.values()),
+        target_year_month=year_month
+    )
+
+
 @main.route('/tags')
 def tag_list():
     """
diff --git a/app/models.py b/app/models.py
index 2e28ce6..03ea892 100644
--- a/app/models.py
+++ b/app/models.py
@@ -23,7 +23,7 @@ class ImageRecord(db.Model):
     filepath = db.Column(db.String(512), nullable=False)
     thumb_path = db.Column(db.String(512))
     hash = db.Column(db.String(64), unique=True, nullable=False)  # SHA256
-    perceptual_hash = db.Column(db.String(16), nullable=True)  # hex of 64-bit hash
+    perceptual_hash = db.Column(db.String(64), nullable=True)  # hex of 256-bit hash
     file_size = db.Column(db.Integer, nullable=True)
     width = db.Column(db.Integer, nullable=True)
     height = db.Column(db.Integer, nullable=True)
@@ -64,3 +64,15 @@ class ArchiveRecord(db.Model):
     artist = db.Column(db.String(255), nullable=True)
     tag_id = db.Column(db.Integer, db.ForeignKey("tag.id", ondelete="SET NULL"), nullable=True)
     tag = db.relationship("Tag")
+
+
+class AppSettings(db.Model):
+    """
+    Key-value store for application settings and version tracking.
+    Used to persist configuration and trigger data migrations on version changes.
+    """
+    __tablename__ = "app_settings"
+    id = db.Column(db.Integer, primary_key=True)
+    key = db.Column(db.String(64), unique=True, nullable=False)
+    value = db.Column(db.Text, nullable=True)
+    updated_at = db.Column(db.DateTime, default=db.func.now(), onupdate=db.func.now())
diff --git a/app/static/js/gallery-infinite.js b/app/static/js/gallery-infinite.js
new file mode 100644
index 0000000..d7cd46d
--- /dev/null
+++ b/app/static/js/gallery-infinite.js
@@ -0,0 +1,475 @@
+// /app/static/js/gallery-infinite.js
+// Infinite scroll gallery with year-month date dividers and timeline navigation
+
+(function() {
+  'use strict';
+
+  // Configuration
+  const CONFIG = {
+    SCROLL_THRESHOLD: 1200,      // px from bottom to trigger load
+    BATCH_SIZE: 30,              // images per API request
+    DEBOUNCE_SCROLL: 100,        // ms debounce for scroll handler
+    DEBOUNCE_RESIZE: 200         // ms debounce for resize handler
+  };
+
+  // State
+  const state = {
+    isLoading: false,
+    hasMore: true,
+    cursor: null,
+    activeTag: null,
+    loadedSections: new Set(),   // year_month keys of loaded sections
+    timelineData: [],
+    currentVisibleSection: null,
+    isJumping: false             // true during jump navigation
+  };
+
+  // DOM references
+  const dom = {
+    container: null,
+    loading: null,
+    end: null,
+    timeline: null,
+    timelineTrack: null
+  };
+
+  // Initialize
+  function init() {
+    dom.container = document.getElementById('galleryInfinite');
+    dom.loading = document.getElementById('galleryLoading');
+    dom.end = document.getElementById('galleryEnd');
+    dom.timeline = document.getElementById('timelineSidebar');
+    dom.timelineTrack = document.getElementById('timelineTrack');
+
+    if (!dom.container) return;
+
+    // Parse initial state from window.galleryState (set by template)
+    if (window.galleryState) {
+      state.cursor = window.galleryState.cursor;
+      state.hasMore = window.galleryState.hasMore;
+      state.activeTag = window.galleryState.activeTag;
+    }
+
+    // Track initially loaded sections
+    parseInitialSections();
+
+    // Load timeline data
+    loadTimeline();
+
+    // Setup event listeners
+    setupScrollListener();
+    setupIntersectionObserver();
+
+    // Check if we need to load more on init (short content)
+    setTimeout(checkScrollPosition, 100);
+  }
+
+  // Parse initially rendered sections
+  function parseInitialSections() {
+    const sections = dom.container.querySelectorAll('.date-section');
+    sections.forEach(section => {
+      const yearMonth = section.dataset.yearMonth;
+      if (yearMonth) {
+        state.loadedSections.add(yearMonth);
+      }
+    });
+  }
+
+  // Fetch more images
+  async function loadMore() {
+    if (state.isLoading || !state.hasMore) return;
+
+    state.isLoading = true;
+    dom.loading.style.display = 'flex';
+
+    try {
+      const params = new URLSearchParams({
+        limit: CONFIG.BATCH_SIZE
+      });
+
+      if (state.cursor) {
+        params.set('cursor', state.cursor);
+      }
+      if (state.activeTag) {
+        params.set('tag', state.activeTag);
+      }
+
+      const response = await fetch(`/api/gallery/scroll?${params}`);
+      const data = await response.json();
+
+      if (data.images && data.images.length > 0) {
+        appendImages(data.images);
+        state.cursor = data.next_cursor;
+        state.hasMore = data.has_more;
+
+        // Notify modal system
+        dispatchGalleryUpdate();
+      }
+
+      if (!data.has_more) {
+        state.hasMore = false;
+        dom.end.style.display = 'block';
+      }
+    } catch (err) {
+      console.error('Failed to load more images:', err);
+    } finally {
+      state.isLoading = false;
+      dom.loading.style.display = 'none';
+    }
+  }
+
+  // Append images to the gallery
+  function appendImages(images) {
+    // Group images by year_month
+    const groups = new Map();
+
+    images.forEach(img => {
+      const key = img.year_month;
+      if (!groups.has(key)) {
+        groups.set(key, {
+          key: key,
+          label: img.year_month_label,
+          images: []
+        });
+      }
+      groups.get(key).images.push(img);
+    });
+
+    // Append to existing sections or create new ones
+    groups.forEach((group, key) => {
+      let section = dom.container.querySelector(`.date-section[data-year-month="${key}"]`);
+
+      if (section) {
+        // Append to existing section
+        const grid = section.querySelector('.gallery-grid');
+        group.images.forEach(img => {
+          grid.appendChild(createImageElement(img));
+        });
+        // Update count
+        updateSectionCount(section);
+      } else {
+        // Create new section
+        section = createDateSection(group.key, group.label, group.images);
+        dom.container.appendChild(section);
+      }
+
+      state.loadedSections.add(key);
+    });
+
+    // Update timeline highlights
+    updateTimelineLoaded();
+  }
+
+  // Create a date section element
+  function createDateSection(yearMonth, label, images) {
+    const section = document.createElement('section');
+    section.className = 'date-section';
+    section.dataset.yearMonth = yearMonth;
+
+    const divider = document.createElement('h2');
+    divider.className = 'date-divider';
+    divider.id = `section-${yearMonth}`;
+    divider.innerHTML = `
+      <span class="date-divider-text">${label}</span>
+      <span class="date-divider-count">${images.length} images</span>
+    `;
+
+    const grid = document.createElement('div');
+    grid.className = 'gallery-grid';
+
+    images.forEach(img => {
+      grid.appendChild(createImageElement(img));
+    });
+
+    section.appendChild(divider);
+    section.appendChild(grid);
+
+    return section;
+  }
+
+  // Create a single image element
+  function createImageElement(img) {
+    const item = document.createElement('div');
+    item.className = 'gallery-item img-clickable';
+    item.dataset.id = img.id;
+    item.dataset.full = img.full_url;
+    item.dataset.type = img.is_video ? 'video' : 'image';
+    item.dataset.filename = img.filename;
+
+    // Build tag overlay HTML
+    let tagsHtml = '';
+    if (img.tags && img.tags.length > 0) {
+      const tagChips = img.tags.map(t => {
+        const displayName = t.name.includes(':') ? t.name.split(':')[1] : t.name;
+        const prefix = t.kind === 'user' ? '#' : '';
+        return `<a class="tag-chip" href="/gallery?tag=${encodeURIComponent(t.name)}" title="Filter by ${t.name}" onclick="event.stopPropagation()">${prefix}${displayName}</a>`;
+      }).join('');
+      tagsHtml = `<div class="tag-overlay">${tagChips}</div>`;
+    }
+
+    // Play overlay for videos
+    const playOverlay = img.is_video ? '<div class="play-overlay"></div>' : '';
+
+    item.innerHTML = `
+      <div class="gallery-thumb" style="background-image: url('${img.thumb_url}');"></div>
+      ${tagsHtml}
+      ${playOverlay}
+      <span class="image-date">${img.date}</span>
+    `;
+
+    return item;
+  }
+
+  // Update section image count
+  function updateSectionCount(section) {
+    const grid = section.querySelector('.gallery-grid');
+    const count = grid.querySelectorAll('.gallery-item').length;
+    const countEl = section.querySelector('.date-divider-count');
+    if (countEl) {
+      countEl.textContent = `${count} images`;
+    }
+  }
+
+  // Scroll handling
+  function setupScrollListener() {
+    let scrollTimeout = null;
+
+    window.addEventListener('scroll', () => {
+      if (scrollTimeout) return;
+      scrollTimeout = setTimeout(() => {
+        scrollTimeout = null;
+        checkScrollPosition();
+      }, CONFIG.DEBOUNCE_SCROLL);
+    }, { passive: true });
+  }
+
+  function checkScrollPosition() {
+    if (state.isLoading || !state.hasMore || state.isJumping) return;
+
+    const scrollBottom = window.innerHeight + window.scrollY;
+    const docHeight = document.documentElement.scrollHeight;
+
+    if (docHeight - scrollBottom < CONFIG.SCROLL_THRESHOLD) {
+      loadMore();
+    }
+  }
+
+  // Intersection observer for tracking visible section
+  function setupIntersectionObserver() {
+    const observer = new IntersectionObserver((entries) => {
+      entries.forEach(entry => {
+        if (entry.isIntersecting) {
+          const yearMonth = entry.target.dataset.yearMonth;
+          if (yearMonth && yearMonth !== state.currentVisibleSection) {
+            state.currentVisibleSection = yearMonth;
+            updateTimelineActive(yearMonth);
+          }
+        }
+      });
+    }, {
+      rootMargin: '-100px 0px -60% 0px',
+      threshold: 0
+    });
+
+    // Observe all date sections
+    const observeSections = () => {
+      dom.container.querySelectorAll('.date-section').forEach(section => {
+        observer.observe(section);
+      });
+    };
+
+    observeSections();
+
+    // Re-observe when new sections are added
+    const mutationObserver = new MutationObserver(() => {
+      observeSections();
+    });
+    mutationObserver.observe(dom.container, { childList: true });
+  }
+
+  // Timeline functions
+  async function loadTimeline() {
+    try {
+      const params = state.activeTag ? `?tag=${encodeURIComponent(state.activeTag)}` : '';
+      const response = await fetch(`/api/gallery/timeline${params}`);
+      const data = await response.json();
+
+      if (data.groups) {
+        state.timelineData = data.groups;
+        renderTimeline();
+      }
+    } catch (err) {
+      console.error('Failed to load timeline:', err);
+      dom.timelineTrack.innerHTML = '<div class="timeline-loading">Failed to load</div>';
+    }
+  }
+
+  function renderTimeline() {
+    if (!dom.timelineTrack || state.timelineData.length === 0) {
+      dom.timelineTrack.innerHTML = '<div class="timeline-loading">No dates</div>';
+      return;
+    }
+
+    // Group by year
+    const yearGroups = new Map();
+    state.timelineData.forEach(item => {
+      if (!yearGroups.has(item.year)) {
+        yearGroups.set(item.year, []);
+      }
+      yearGroups.get(item.year).push(item);
+    });
+
+    let html = '';
+
+    yearGroups.forEach((months, year) => {
+      html += `<div class="timeline-year-group" data-year="${year}">`;
+      html += `<div class="timeline-year">${year}</div>`;
+      html += '<div class="timeline-months">';
+
+      months.forEach(month => {
+        const isLoaded = state.loadedSections.has(month.key);
+        const loadedClass = isLoaded ? ' loaded' : '';
+
+        html += `
+          <a class="timeline-month${loadedClass}"
+             data-year-month="${month.key}"
+             href="#section-${month.key}"
+             title="${month.label}: ${month.count} images">
+            <span class="timeline-month-label">${month.short_label}</span>
+            <span class="timeline-month-count">${month.count}</span>
+          </a>
+        `;
+      });
+
+      html += '</div></div>';
+    });
+
+    dom.timelineTrack.innerHTML = html;
+
+    // Add click handlers for timeline navigation
+    dom.timelineTrack.querySelectorAll('.timeline-month').forEach(el => {
+      el.addEventListener('click', handleTimelineClick);
+    });
+
+    // Update active state
+    if (state.currentVisibleSection) {
+      updateTimelineActive(state.currentVisibleSection);
+    }
+  }
+
+  function handleTimelineClick(e) {
+    e.preventDefault();
+
+    const yearMonth = e.currentTarget.dataset.yearMonth;
+    if (!yearMonth) return;
+
+    // Check if section is already loaded
+    const existingSection = document.getElementById(`section-${yearMonth}`);
+
+    if (existingSection) {
+      // Scroll to existing section
+      existingSection.scrollIntoView({ behavior: 'smooth', block: 'start' });
+    } else {
+      // Jump to this date - fetch and load
+      jumpToDate(yearMonth);
+    }
+  }
+
+  async function jumpToDate(yearMonth) {
+    if (state.isJumping) return;
+
+    state.isJumping = true;
+    dom.loading.style.display = 'flex';
+
+    try {
+      const params = new URLSearchParams({
+        year_month: yearMonth,
+        limit: CONFIG.BATCH_SIZE
+      });
+
+      if (state.activeTag) {
+        params.set('tag', state.activeTag);
+      }
+
+      const response = await fetch(`/api/gallery/jump?${params}`);
+      const data = await response.json();
+
+      if (data.images && data.images.length > 0) {
+        // Clear existing content and replace with jumped-to content
+        dom.container.innerHTML = '';
+        state.loadedSections.clear();
+
+        // Add images
+        appendImages(data.images);
+
+        // Update cursor for continued scrolling
+        state.cursor = data.next_cursor;
+        state.hasMore = data.has_more;
+
+        // Reset end marker
+        if (data.has_more) {
+          dom.end.style.display = 'none';
+        } else {
+          dom.end.style.display = 'block';
+        }
+
+        // Scroll to top of new content
+        window.scrollTo({ top: 0, behavior: 'instant' });
+
+        // Update timeline
+        updateTimelineLoaded();
+
+        // Notify modal system
+        dispatchGalleryUpdate();
+      }
+    } catch (err) {
+      console.error('Failed to jump to date:', err);
+    } finally {
+      state.isJumping = false;
+      dom.loading.style.display = 'none';
+    }
+  }
+
+  function updateTimelineActive(yearMonth) {
+    // Remove active from all
+    dom.timelineTrack.querySelectorAll('.timeline-month.active').forEach(el => {
+      el.classList.remove('active');
+    });
+
+    // Add active to current
+    const activeEl = dom.timelineTrack.querySelector(`.timeline-month[data-year-month="${yearMonth}"]`);
+    if (activeEl) {
+      activeEl.classList.add('active');
+
+      // Scroll timeline to keep active visible
+      const track = dom.timelineTrack;
+      const elRect = activeEl.getBoundingClientRect();
+      const trackRect = track.getBoundingClientRect();
+
+      if (elRect.top < trackRect.top || elRect.bottom > trackRect.bottom) {
+        activeEl.scrollIntoView({ behavior: 'smooth', block: 'center' });
+      }
+    }
+  }
+
+  function updateTimelineLoaded() {
+    dom.timelineTrack.querySelectorAll('.timeline-month').forEach(el => {
+      const yearMonth = el.dataset.yearMonth;
+      if (state.loadedSections.has(yearMonth)) {
+        el.classList.add('loaded');
+      }
+    });
+  }
+
+  // Dispatch event for modal system integration
+  function dispatchGalleryUpdate() {
+    document.dispatchEvent(new CustomEvent('galleryUpdated'));
+  }
+
+  // Initialize on DOM ready
+  if (document.readyState === 'loading') {
+    document.addEventListener('DOMContentLoaded', init);
+  } else {
+    init();
+  }
+})();
diff --git a/app/static/js/modal-pagination.js b/app/static/js/modal-pagination.js
index 2fba69b..5ed081d 100644
--- a/app/static/js/modal-pagination.js
+++ b/app/static/js/modal-pagination.js
@@ -28,11 +28,16 @@ document.addEventListener('DOMContentLoaded', () => {
   let dragStartY = 0;
   let dragMoved = false;
 
+  // Legacy pagination inputs (for non-infinite-scroll pages)
   const hasNextPageInput = document.getElementById('hasNextPage');
   const nextPageUrlInput = document.getElementById('nextPageUrl');
   const hasPrevPageInput = document.getElementById('hasPrevPage');
   const prevPageUrlInput = document.getElementById('prevPageUrl');
 
+  // Check if we're in infinite scroll mode
+  // Infinite scroll mode is when galleryState exists (set by gallery.html template)
+  const isInfiniteScrollMode = typeof window.galleryState !== 'undefined';
+
   // ---------------------------
   // Tag editor helpers
   // ---------------------------
@@ -158,9 +163,11 @@ document.addEventListener('DOMContentLoaded', () => {
 
   async function fetchAutocomplete(query) {
     try {
+      // Exclude system-managed tag kinds from autocomplete (archive, post, source)
+      const excludeKinds = 'archive,post,source';
       const url = query
-        ? `/api/tags/search?q=${encodeURIComponent(query)}&limit=8&exclude_kind=archive`
-        : `/api/tags/search?limit=8&exclude_kind=archive`;
+        ? `/api/tags/search?q=${encodeURIComponent(query)}&limit=8&exclude_kind=${excludeKinds}`
+        : `/api/tags/search?limit=8&exclude_kind=${excludeKinds}`;
       const r = await fetch(url);
       const j = await r.json();
       renderAutocomplete(j.tags || []);
@@ -316,7 +323,12 @@ document.addEventListener('DOMContentLoaded', () => {
   function showNext() {
     if (currentIndex < images.length - 1) {
       updateImage(currentIndex + 1);
+    } else if (isInfiniteScrollMode) {
+      // In infinite scroll mode, just stay at the last image
+      // User needs to scroll the gallery to load more
+      return;
     } else if (hasNextPageInput?.value === "true") {
+      // Legacy pagination mode - fetch next page
       fetch(nextPageUrlInput.value)
         .then(res => res.text())
         .then(html => {
@@ -349,7 +361,11 @@ document.addEventListener('DOMContentLoaded', () => {
   function showPrev() {
     if (currentIndex > 0) {
       updateImage(currentIndex - 1);
+    } else if (isInfiniteScrollMode) {
+      // In infinite scroll mode, just stay at the first image
+      return;
     } else if (hasPrevPageInput?.value === "true") {
+      // Legacy pagination mode - fetch previous page
       fetch(prevPageUrlInput.value)
         .then(res => res.text())
         .then(html => {
@@ -480,6 +496,11 @@ document.addEventListener('DOMContentLoaded', () => {
     images = Array.from(document.querySelectorAll('.img-clickable'));
   });
 
+  // Listen for gallery infinite scroll updates to refresh the images array
+  document.addEventListener('galleryUpdated', () => {
+    images = Array.from(document.querySelectorAll('.img-clickable'));
+  });
+
   window.addEventListener('popstate', () => {
     if (modal.classList.contains('active')) {
       closeModal();
diff --git a/app/static/js/showcase.js b/app/static/js/showcase.js
index 731d74d..e3ebc87 100644
--- a/app/static/js/showcase.js
+++ b/app/static/js/showcase.js
@@ -97,10 +97,28 @@
   }
 
   function checkScrollPosition() {
-    const scrollBottom = window.innerHeight + window.scrollY;
-    const docHeight = document.documentElement.scrollHeight;
+    // For masonry layouts, we need to check if the SHORTEST column is near the viewport bottom,
+    // not the overall page bottom. Otherwise, a tall image in one column prevents loading
+    // even when other columns have empty space visible.
 
-    if (docHeight - scrollBottom < SCROLL_THRESHOLD) {
+    // First, update accurate column heights
+    updateColumnHeights();
+
+    // Find the shortest column's bottom position relative to viewport
+    const shortestColumnIndex = getShortestColumnIndex();
+    const shortestColumn = columns[shortestColumnIndex];
+    if (!shortestColumn) return;
+
+    const columnRect = shortestColumn.getBoundingClientRect();
+    const columnBottom = columnRect.bottom;  // Distance from viewport top to column bottom
+    const viewportHeight = window.innerHeight;
+
+    // If the shortest column's bottom is within SCROLL_THRESHOLD of the viewport bottom, load more
+    // columnBottom - viewportHeight = how far below the viewport the column extends
+    // If this is negative or small, the column end is visible or nearly visible
+    const distanceFromViewportBottom = columnBottom - viewportHeight;
+
+    if (distanceFromViewportBottom < SCROLL_THRESHOLD) {
       loadMore();
     }
   }
diff --git a/app/static/style.css b/app/static/style.css
index b8fcd12..3ae27d3 100644
--- a/app/static/style.css
+++ b/app/static/style.css
@@ -378,14 +378,25 @@ header {
   display: flex;
   align-items: center;
   justify-content: center;
-  max-width: 100%;
+  width: 100%;
+  max-width: calc(100% - 300px); /* Account for tag editor */
+  height: calc(100vh - 140px);
   max-height: calc(100vh - 140px);
   overflow: hidden;
   cursor: default;
 }
-.modal-image-wrapper.zoomed { overflow: auto; cursor: grab; }
+.modal-image-wrapper.zoomed {
+  overflow: auto;
+  cursor: grab;
+  /* Enable scrolling by removing flex centering when zoomed */
+  display: block;
+}
 .modal-image-wrapper.zoomed img {
-  width: auto; height: auto; max-width: none; max-height: none;
+  width: auto;
+  height: auto;
+  max-width: none;
+  max-height: none;
+  cursor: grab;
 }
 .modal-image-wrapper img {
   max-width: 100%;
@@ -404,6 +415,15 @@ header {
   width: 90vw; height: auto; max-height: none;
 }
 
+/* On smaller screens, full width for image wrapper */
+@media (max-width: 900px) {
+  .modal-image-wrapper {
+    max-width: 100%;
+    height: auto;
+    max-height: 60vh;
+  }
+}
+
 /* Modal navigation buttons - cleaner pill style */
 .modal-button {
   position: absolute;
@@ -1191,3 +1211,258 @@ select.form-input optgroup {
   overflow-wrap: anywhere;          /* allows breaking long tokens */
   word-break: break-word;
 }
+
+/*------------------------------------------------------------------------------
+  Gallery Infinite Scroll Layout
+------------------------------------------------------------------------------*/
+.gallery-infinite-container {
+  display: flex;
+  min-height: 100vh;
+  max-width: 1800px;
+  margin: 0 auto;
+  position: relative;
+}
+
+/* Timeline Sidebar - positioned relative to gallery container */
+.timeline-sidebar {
+  position: sticky;
+  top: 60px;
+  height: calc(100vh - 60px);
+  width: 70px;
+  min-width: 70px;
+  background: rgba(0,0,0,0.3);
+  border-right: 1px solid rgba(255,255,255,0.08);
+  z-index: 50;
+  display: flex;
+  flex-direction: column;
+  padding: 0.5rem 0;
+  overflow-y: auto;
+  scrollbar-width: thin;
+  scrollbar-color: rgba(255,255,255,0.2) transparent;
+}
+.timeline-sidebar::-webkit-scrollbar {
+  width: 4px;
+}
+.timeline-sidebar::-webkit-scrollbar-track {
+  background: transparent;
+}
+.timeline-sidebar::-webkit-scrollbar-thumb {
+  background: rgba(255,255,255,0.2);
+  border-radius: 2px;
+}
+
+.timeline-track {
+  display: flex;
+  flex-direction: column;
+  padding: 0 6px;
+}
+
+.timeline-loading {
+  font-size: 0.7rem;
+  color: var(--text-muted);
+  padding: 0.5rem;
+  text-align: center;
+}
+
+.timeline-year-group {
+  margin-bottom: 0.5rem;
+}
+
+.timeline-year {
+  font-size: 0.8rem;
+  font-weight: 600;
+  color: var(--text);
+  padding: 0.5rem 0.25rem 0.25rem;
+  text-align: center;
+  position: sticky;
+  top: 0;
+  background: linear-gradient(to bottom, rgba(10,10,10,0.95), rgba(10,10,10,0.8));
+  z-index: 1;
+  border-bottom: 1px solid rgba(255,255,255,0.1);
+}
+
+.timeline-months {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  padding-top: 4px;
+}
+
+.timeline-month {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0.35rem 0.5rem;
+  font-size: 0.7rem;
+  color: var(--text-muted);
+  border-radius: 4px;
+  cursor: pointer;
+  transition: all 0.15s ease;
+  text-decoration: none;
+}
+.timeline-month:hover {
+  background: rgba(255,255,255,0.12);
+  color: var(--text);
+}
+.timeline-month.active {
+  background: var(--btn-primary);
+  color: white;
+}
+.timeline-month.loaded {
+  color: var(--text-dim);
+}
+.timeline-month-label {
+  font-weight: 500;
+}
+.timeline-month-count {
+  font-size: 0.6rem;
+  opacity: 0.7;
+}
+
+/* Main gallery area - flex child next to timeline */
+.gallery-main {
+  flex: 1;
+  padding: 0 0.5rem;
+  min-width: 0;
+}
+
+.gallery-header {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  padding: 0.5rem 0 1rem;
+  gap: 0.5rem;
+}
+.gallery-header h1 {
+  margin: 0;
+  font-size: 1.5rem;
+}
+
+.active-filter {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.5rem 1rem;
+  background: rgba(255,255,255,0.08);
+  border-radius: 999px;
+  font-size: 0.9rem;
+  color: var(--text-dim);
+}
+.filter-tag {
+  color: var(--link);
+  font-weight: 500;
+}
+.clear-filter {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: rgba(255,255,255,0.1);
+  color: var(--text-muted);
+  text-decoration: none;
+  font-size: 0.9rem;
+  line-height: 1;
+  transition: all 0.15s ease;
+}
+.clear-filter:hover {
+  background: rgba(255,255,255,0.2);
+  color: var(--text);
+}
+
+/* Gallery content area */
+.gallery-infinite {
+  min-height: 50vh;
+}
+
+.gallery-empty {
+  text-align: center;
+  padding: 4rem 1rem;
+  color: var(--text-muted);
+}
+
+/* Date sections */
+.date-section {
+  margin-bottom: 1.5rem;
+}
+
+.date-divider {
+  display: flex;
+  align-items: center;
+  gap: 1rem;
+  padding: 0.75rem 0.5rem;
+  margin: 0 0 0.5rem 0;
+  border-bottom: 1px solid rgba(255,255,255,0.1);
+  position: sticky;
+  top: 50px;
+  background: linear-gradient(to bottom, var(--bg) 0%, var(--bg) 85%, transparent 100%);
+  z-index: 10;
+}
+
+.date-divider-text {
+  font-size: 1.1rem;
+  font-weight: 500;
+  color: var(--text);
+}
+
+.date-divider-count {
+  font-size: 0.8rem;
+  color: var(--text-muted);
+  background: rgba(255,255,255,0.08);
+  padding: 0.2rem 0.6rem;
+  border-radius: 999px;
+}
+
+/* Loading indicator */
+.gallery-loading {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 0.75rem;
+  padding: 2rem;
+  color: var(--text-muted);
+}
+
+.loading-spinner {
+  display: inline-block;
+  width: 20px;
+  height: 20px;
+  border: 2px solid rgba(255,255,255,0.2);
+  border-top-color: var(--btn-primary);
+  border-radius: 50%;
+  animation: spin 0.8s linear infinite;
+}
+
+@keyframes spin {
+  to { transform: rotate(360deg); }
+}
+
+.gallery-end {
+  text-align: center;
+  padding: 2rem;
+  color: var(--text-muted);
+  font-style: italic;
+  border-top: 1px solid rgba(255,255,255,0.05);
+}
+
+/* Play overlay with triangle icon */
+.play-overlay::before {
+  content: '';
+  width: 0;
+  height: 0;
+  border-style: solid;
+  border-width: 20px 0 20px 35px;
+  border-color: transparent transparent transparent rgba(255,255,255,0.9);
+  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.5));
+}
+
+/* Mobile: hide timeline sidebar */
+@media (max-width: 768px) {
+  .timeline-sidebar {
+    display: none;
+  }
+  .date-divider {
+    top: 45px;
+  }
+}
diff --git a/app/templates/_gallery_item.html b/app/templates/_gallery_item.html
new file mode 100644
index 0000000..fda0c31
--- /dev/null
+++ b/app/templates/_gallery_item.html
@@ -0,0 +1,40 @@
+<!-- /app/templates/_gallery_item.html -->
+<div class="gallery-item img-clickable"
+     data-id="{{ image.id }}"
+     data-full="{{ url_for('main.serve_image', filename=image.filepath | replace('/images/', '') ) }}"
+     data-type="{{ 'video' if image.filename.lower().endswith(('.mp4', '.mov')) else 'image' }}"
+     data-filename="{{ image.filename }}">
+
+  <div class="gallery-thumb"
+       style="background-image: url('{{ url_for('main.serve_image', filename=(image.thumb_path or image.filepath) | replace('/images/', '') ) }}');"></div>
+
+  {% set visible_tags = image.tags | selectattr('kind', 'ne', 'archive') | list %}
+  {% if visible_tags %}
+    <div class="tag-overlay">
+      {% for t in visible_tags %}
+        <a class="tag-chip"
+           href="{{ url_for('main.gallery', tag=t.name) }}"
+           title="Filter by {{ t.name }}"
+           onclick="event.stopPropagation()">
+          {% if t.kind == 'artist' %}
+            {{ t.name.split(':', 1)[1] if ':' in t.name else t.name }}
+          {% elif t.kind == 'character' %}
+            {{ t.name.split(':', 1)[1] if ':' in t.name else t.name }}
+          {% elif t.kind == 'series' %}
+            {{ t.name.split(':', 1)[1] if ':' in t.name else t.name }}
+          {% elif t.kind == 'rating' %}
+            {{ t.name.split(':', 1)[1] if ':' in t.name else t.name }}
+          {% else %}
+            #{{ t.name }}
+          {% endif %}
+        </a>
+      {% endfor %}
+    </div>
+  {% endif %}
+
+  {% if image.filename.lower().endswith(('.mp4', '.mov')) %}
+    <div class="play-overlay"></div>
+  {% endif %}
+
+  <span class="image-date">{{ image.taken_at or image.imported_at | datetimeformat }}</span>
+</div>
diff --git a/app/templates/_gallery_modal.html b/app/templates/_gallery_modal.html
new file mode 100644
index 0000000..13663ff
--- /dev/null
+++ b/app/templates/_gallery_modal.html
@@ -0,0 +1,26 @@
+<!-- /app/templates/_gallery_modal.html -->
+<div id="imageModal" class="modal">
+  <div class="modal-content">
+    <button id="modalClose" class="modal-close-btn" title="Close (ESC)">×</button>
+    <button id="modalPrev" class="modal-button modal-prev">‹</button>
+    <button id="modalNext" class="modal-button modal-next">›</button>
+    <span class="modal-close-hint">ESC to close</span>
+
+    <div class="modal-body">
+      <div id="modalImageWrapper" class="modal-image-wrapper">
+        <img id="modalImage" src="" alt="Full View">
+      </div>
+
+      <div id="modalTagEditor" class="tag-editor" data-image-id="">
+        <div id="modalTagList" class="tags"></div>
+        <form id="modalTagForm" class="tag-form" autocomplete="off">
+          <div class="tag-form-wrapper">
+            <input type="text" id="tagInput" name="name" placeholder="Add tag..." autocomplete="off">
+            <div id="tagAutocomplete" class="tag-autocomplete"></div>
+          </div>
+          <button type="submit">Add</button>
+        </form>
+      </div>
+    </div>
+  </div>
+</div>
diff --git a/app/templates/gallery.html b/app/templates/gallery.html
index 0ae9e75..ad32a5f 100644
--- a/app/templates/gallery.html
+++ b/app/templates/gallery.html
@@ -3,14 +3,73 @@
 {% block title %}Gallery{% endblock %}
 
 {% block content %}
-<h1 style="text-align:center; margin-top: 1rem;">Gallery</h1>
+<div class="gallery-infinite-container">
+  <!-- Timeline Scrollbar (left sidebar) -->
+  <aside id="timelineSidebar" class="timeline-sidebar">
+    <div id="timelineTrack" class="timeline-track">
+      <!-- Populated by JS with year-month markers -->
+      <div class="timeline-loading">Loading...</div>
+    </div>
+  </aside>
 
-<!-- Gallery Grid -->
-{% include '_gallery_grid.html' %}
+  <!-- Main Gallery Content -->
+  <main class="gallery-main">
+    <div class="gallery-header">
+      <h1>Gallery</h1>
+      {% if active_tag %}
+        <div class="active-filter">
+          Filtered by: <span class="filter-tag">{{ active_tag }}</span>
+          <a href="{{ url_for('main.gallery') }}" class="clear-filter" title="Clear filter">×</a>
+        </div>
+      {% endif %}
+    </div>
 
-<!-- Floating Pagination Bar -->
-{% if images.pages > 1 %}
-{% include '_pagination_floating.html' %}
-{% endif %}
+    <!-- Gallery Grid with Date Sections -->
+    <div id="galleryInfinite" class="gallery-infinite">
+      {% for year_month_key, year_month_label, images in grouped_images %}
+        <section class="date-section" data-year-month="{{ year_month_key }}">
+          <h2 class="date-divider" id="section-{{ year_month_key }}">
+            <span class="date-divider-text">{{ year_month_label }}</span>
+            <span class="date-divider-count">{{ images|length }} images</span>
+          </h2>
+          <div class="gallery-grid">
+            {% for image in images %}
+              {% include '_gallery_item.html' %}
+            {% endfor %}
+          </div>
+        </section>
+      {% else %}
+        <div class="gallery-empty">
+          <p>No images found{% if active_tag %} for tag "{{ active_tag }}"{% endif %}.</p>
+        </div>
+      {% endfor %}
+    </div>
 
+    <!-- Loading indicator -->
+    <div id="galleryLoading" class="gallery-loading" style="display:none;">
+      <span class="loading-spinner"></span>
+      <span>Loading more images...</span>
+    </div>
+
+    <!-- End of content marker -->
+    <div id="galleryEnd" class="gallery-end" style="display:none;">
+      No more images
+    </div>
+  </main>
+</div>
+
+<!-- Modal -->
+{% include '_gallery_modal.html' %}
+
+<!-- Pass initial state to JS -->
+<script>
+  window.galleryState = {
+    cursor: {{ initial_cursor | tojson | safe if initial_cursor else 'null' }},
+    hasMore: {{ 'true' if has_more else 'false' }},
+    activeTag: {{ active_tag | tojson | safe if active_tag else 'null' }}
+  };
+</script>
+
+<script src="{{ url_for('static', filename='js/gallery-infinite.js') }}"></script>
+<script src="{{ url_for('static', filename='js/modal-pagination.js') }}"></script>
 {% endblock %}
diff --git a/app/templates/layout.html b/app/templates/layout.html
index b07c1de..f9147a0 100644
--- a/app/templates/layout.html
+++ b/app/templates/layout.html
@@ -37,12 +37,6 @@
   </div>
 </div>
 
-{% if request.endpoint == 'main.gallery' %}
-  <input type="hidden" id="hasNextPage" value="{{ has_next|lower }}">
-  <input type="hidden" id="nextPageUrl" value="{{ next_page_url }}">
-  <input type="hidden" id="hasPrevPage" value="{{ has_prev|lower }}">
-  <input type="hidden" id="prevPageUrl" value="{{ prev_page_url }}">
-{% endif %}
 
 </body>
 </html>
diff --git a/app/utils/image_importer.py b/app/utils/image_importer.py
index c1ff9fa..105483d 100644
--- a/app/utils/image_importer.py
+++ b/app/utils/image_importer.py
@@ -50,21 +50,43 @@ IMPORT_STATS_PATH = "/import/stats.json"
 
 
 def load_import_settings() -> dict:
-    """Load import filter settings from file or environment."""
+    """
+    Load import filter settings from database, with file and environment fallbacks.
+    Priority: DB settings > file settings > environment variables
+    """
+    # Start with environment defaults
     defaults = {
         "min_width": int(os.environ.get("IMPORT_MIN_WIDTH", "0")),
         "min_height": int(os.environ.get("IMPORT_MIN_HEIGHT", "0")),
         "skip_transparent": os.environ.get("IMPORT_SKIP_TRANSPARENT", "false").lower() == "true",
         "transparency_threshold": float(os.environ.get("IMPORT_TRANSPARENCY_THRESHOLD", "0.9")),
-        "phash_threshold": int(os.environ.get("IMPORT_PHASH_THRESHOLD", "2")),
+        "skip_single_color": os.environ.get("IMPORT_SKIP_SINGLE_COLOR", "true").lower() == "true",
+        "single_color_threshold": float(os.environ.get("IMPORT_SINGLE_COLOR_THRESHOLD", "0.95")),
+        "single_color_tolerance": int(os.environ.get("IMPORT_SINGLE_COLOR_TOLERANCE", "30")),
+        "phash_threshold": int(os.environ.get("IMPORT_PHASH_THRESHOLD", "10")),  # Default for 256-bit
+        "supersede_smaller": os.environ.get("IMPORT_SUPERSEDE_SMALLER", "true").lower() == "true",
     }
+
+    # Try to load from file (legacy support)
     try:
         if os.path.exists(IMPORT_SETTINGS_PATH):
             with open(IMPORT_SETTINGS_PATH, "r") as f:
                 file_settings = json.load(f)
                 defaults.update(file_settings)
     except Exception as e:
-        print(f"[WARN] Failed to load import settings: {e}")
+        print(f"[WARN] Failed to load import settings from file: {e}")
+
+    # Try to load from database (preferred)
+    try:
+        from app.utils.version_migration import get_import_settings
+        db_settings = get_import_settings()
+        # Only override if DB has non-default values
+        for key, value in db_settings.items():
+            if value is not None:
+                defaults[key] = value
+    except Exception as e:
+        print(f"[WARN] Failed to load import settings from DB: {e}")
+
     return defaults
 
 
@@ -106,6 +128,136 @@ def is_mostly_transparent(file_path: str, threshold: float = 0.9) -> bool:
         print(f"[WARN] Failed to check transparency for {file_path}: {e}")
         return False
 
+
+def is_mostly_single_color(file_path: str, threshold: float = 0.95, tolerance: int = 30) -> bool:
+    """
+    Check if an image is mostly a single color (> threshold % of pixels are similar).
+    Uses color distance tolerance to group similar colors.
+
+    Args:
+        file_path: Path to the image file
+        threshold: Percentage of pixels that must be similar (0.0-1.0, default 0.95 = 95%)
+        tolerance: Maximum color distance to be considered "same" color (0-255 per channel, default 30)
+
+    Returns:
+        True if the image is mostly a single solid color
+    """
+    try:
+        with Image.open(file_path) as img:
+            # Convert to RGB for consistent color comparison
+            if img.mode in ("RGBA", "LA"):
+                # For images with alpha, only consider non-transparent pixels
+                img_rgba = img.convert("RGBA") if img.mode != "RGBA" else img
+                pixels = list(img_rgba.getdata())
+                # Filter out mostly transparent pixels (alpha < 128)
+                opaque_pixels = [(r, g, b) for r, g, b, a in pixels if a >= 128]
+                if len(opaque_pixels) == 0:
+                    return True  # Fully transparent = effectively single color
+                pixels = opaque_pixels
+            elif img.mode == "P":
+                img = img.convert("RGB")
+                pixels = list(img.getdata())
+            elif img.mode == "L":
+                # Grayscale - convert to RGB tuples
+                pixels = [(p, p, p) for p in img.getdata()]
+            else:
+                if img.mode != "RGB":
+                    img = img.convert("RGB")
+                pixels = list(img.getdata())
+
+            if len(pixels) == 0:
+                return True
+
+            # Sample pixels for performance on large images
+            total_pixels = len(pixels)
+            if total_pixels > 10000:
+                # Sample evenly distributed pixels
+                step = total_pixels // 10000
+                pixels = pixels[::step]
+
+            # Find the dominant color (most common pixel or average of sampled area)
+            # Use the pixel at center as reference
+            center_idx = len(pixels) // 2
+            ref_color = pixels[center_idx]
+
+            # Count pixels within tolerance of reference color
+            similar_count = 0
+            for pixel in pixels:
+                if isinstance(pixel, int):
+                    pixel = (pixel, pixel, pixel)
+                # Calculate color distance (simple RGB distance)
+                dist = abs(pixel[0] - ref_color[0]) + abs(pixel[1] - ref_color[1]) + abs(pixel[2] - ref_color[2])
+                if dist <= tolerance * 3:  # tolerance per channel * 3 channels
+                    similar_count += 1
+
+            similarity_ratio = similar_count / len(pixels)
+            return similarity_ratio > threshold
+
+    except Exception as e:
+        print(f"[WARN] Failed to check single color for {file_path}: {e}")
+        return False
+
+
+def supersede_image(old_record: "ImageRecord", new_filepath: str, new_thumb_path: str,
+                    new_hash: str, new_phash, new_metadata: dict, new_filename: str) -> "ImageRecord":
+    """
+    Replace a smaller image with a larger version, preserving tags and metadata.
+
+    Args:
+        old_record: The existing ImageRecord to supersede
+        new_filepath: Path to the new larger image file
+        new_thumb_path: Path to the new thumbnail
+        new_hash: SHA256 hash of the new file
+        new_phash: Perceptual hash of the new image
+        new_metadata: Metadata dict for the new image
+        new_filename: Original filename of the new image
+
+    Returns:
+        The updated ImageRecord
+    """
+    # Store old file paths for cleanup
+    old_filepath = old_record.filepath
+    old_thumb_path = old_record.thumb_path
+
+    print(f"[SUPERSEDE] Replacing {old_record.filename} ({old_record.width}x{old_record.height}) "
+          f"with {new_filename} ({new_metadata['width']}x{new_metadata['height']})")
+
+    # Update record with new file info
+    old_record.filename = new_filename
+    old_record.filepath = new_filepath
+    old_record.thumb_path = new_thumb_path
+    old_record.hash = new_hash
+    old_record.perceptual_hash = str(new_phash) if new_phash else None
+    old_record.file_size = new_metadata["file_size"]
+    old_record.width = new_metadata["width"]
+    old_record.height = new_metadata["height"]
+    old_record.format = new_metadata["format"]
+    # Keep the earlier taken_at date (prefer original date)
+    if new_metadata.get("taken_at") and old_record.taken_at:
+        if new_metadata["taken_at"] < old_record.taken_at:
+            old_record.taken_at = new_metadata["taken_at"]
+    elif new_metadata.get("taken_at") and not old_record.taken_at:
+        old_record.taken_at = new_metadata["taken_at"]
+    # Don't update imported_at - keep original import time
+
+    # Delete old files
+    try:
+        if old_filepath and os.path.exists(old_filepath):
+            os.remove(old_filepath)
+            print(f"[SUPERSEDE] Deleted old file: {old_filepath}")
+    except Exception as e:
+        print(f"[WARN] Failed to delete old file {old_filepath}: {e}")
+
+    try:
+        if old_thumb_path and os.path.exists(old_thumb_path):
+            os.remove(old_thumb_path)
+            print(f"[SUPERSEDE] Deleted old thumbnail: {old_thumb_path}")
+    except Exception as e:
+        print(f"[WARN] Failed to delete old thumbnail {old_thumb_path}: {e}")
+
+    return old_record
+
+
 # Regex for multi-part detection
 RAR_PART_RE    = re.compile(r"\.part(\d+)\.rar$", re.IGNORECASE)
 SEVENZ_PART_RE = re.compile(r"\.7z\.(\d{3})$", re.IGNORECASE)
@@ -233,19 +385,25 @@ def import_images_task(source_dir: str, dest_dir: str) -> str:
     min_height = settings.get("min_height", 0)
     skip_transparent = settings.get("skip_transparent", False)
     transparency_threshold = settings.get("transparency_threshold", 0.9)
-
+    skip_single_color = settings.get("skip_single_color", True)
+    single_color_threshold = settings.get("single_color_threshold", 0.95)
+    single_color_tolerance = settings.get("single_color_tolerance", 30)
     phash_threshold = settings.get("phash_threshold", 2)
+    supersede_smaller = settings.get("supersede_smaller", True)
 
     print(f"[INFO] Import settings: min_width={min_width}, min_height={min_height}, "
           f"skip_transparent={skip_transparent}, transparency_threshold={transparency_threshold}, "
-          f"phash_threshold={phash_threshold}")
+          f"skip_single_color={skip_single_color}, single_color_threshold={single_color_threshold}, "
+          f"phash_threshold={phash_threshold}, supersede_smaller={supersede_smaller}")
 
     # Statistics tracking
     stats = {
         "total_processed": 0,
         "total_imported": 0,
+        "total_superseded": 0,
         "filtered_by_dimension": 0,
         "filtered_by_transparency": 0,
+        "filtered_by_single_color": 0,
         "filtered_by_duplicate": 0,
     }
 
@@ -254,8 +412,9 @@ def import_images_task(source_dir: str, dest_dir: str) -> str:
     batch_counter = 0
 
     # Preload existing pHashes to avoid N+1 lookups
+    # Format: (phash, width, height, image_id) for supersede functionality
     existing_phashes = [
-        (imagehash.hex_to_hash(img.perceptual_hash), img.width, img.height)
+        (imagehash.hex_to_hash(img.perceptual_hash), img.width, img.height, img.id)
         for img in ImageRecord.query.filter(ImageRecord.perceptual_hash != None).all()
     ]
 
@@ -320,24 +479,34 @@ def import_images_task(source_dir: str, dest_dir: str) -> str:
                         stats["filtered_by_transparency"] += 1
                         continue
 
-                added, phash, _rec = import_single_file(
+                # Apply single-color filter (skip images that are mostly one solid color)
+                if skip_single_color and lower.endswith((".png", ".jpg", ".jpeg", ".gif", ".webp", ".bmp")):
+                    if is_mostly_single_color(full_path, single_color_threshold, single_color_tolerance):
+                        print(f"[SKIP] Mostly single color: {file}")
+                        stats["filtered_by_single_color"] += 1
+                        continue
+
+                added, phash, _rec, superseded = import_single_file(
                     src_path=full_path,
                     dest_dir=dest_dir,
                     artist=artist_dir,
                     existing_phashes=existing_phashes,
-                    phash_threshold=phash_threshold
+                    phash_threshold=phash_threshold,
+                    supersede_smaller=supersede_smaller
                 )
                 if added:
                     imported.append(file)
-                    stats["total_imported"] += 1
+                    if superseded:
+                        stats["total_superseded"] += 1
+                    else:
+                        stats["total_imported"] += 1
                 elif _rec is None and phash is None:
                     # Was a duplicate
                     stats["filtered_by_duplicate"] += 1
 
-                if phash:
-                    md = extract_metadata(full_path)
-                    if md.get("width") and md.get("height"):
-                        existing_phashes.append((phash, md["width"], md["height"]))
+                # Add new image's phash to the tracking list (for fresh imports only, not supersedes)
+                if phash and _rec and not superseded:
+                    existing_phashes.append((phash, _rec.width, _rec.height, _rec.id))
 
                 batch_counter += 1
                 if batch_counter >= batch_size:
@@ -354,7 +523,9 @@ def import_images_task(source_dir: str, dest_dir: str) -> str:
     # Save stats
     save_import_stats(stats)
 
-    summary = f"Imported {len(imported)} items. Filtered: {stats['filtered_by_dimension']} by size, {stats['filtered_by_transparency']} by transparency."
+    summary = (f"Imported {stats['total_imported']} items, superseded {stats['total_superseded']} smaller versions. "
+               f"Filtered: {stats['filtered_by_dimension']} by size, {stats['filtered_by_transparency']} by transparency, "
+               f"{stats['filtered_by_single_color']} by single color, {stats['filtered_by_duplicate']} duplicates.")
     print(f"[INFO] {summary}")
     return summary
 
@@ -368,14 +539,19 @@ def process_archive(archive_path, dest_dir, artist, existing_phashes, settings=N
     if settings is None:
         settings = load_import_settings()
     if stats is None:
-        stats = {"total_processed": 0, "total_imported": 0, "filtered_by_dimension": 0,
-                 "filtered_by_transparency": 0, "filtered_by_duplicate": 0}
+        stats = {"total_processed": 0, "total_imported": 0, "total_superseded": 0,
+                 "filtered_by_dimension": 0, "filtered_by_transparency": 0,
+                 "filtered_by_single_color": 0, "filtered_by_duplicate": 0}
 
     min_width = settings.get("min_width", 0)
     min_height = settings.get("min_height", 0)
     skip_transparent = settings.get("skip_transparent", False)
     transparency_threshold = settings.get("transparency_threshold", 0.9)
+    skip_single_color = settings.get("skip_single_color", True)
+    single_color_threshold = settings.get("single_color_threshold", 0.95)
+    single_color_tolerance = settings.get("single_color_tolerance", 30)
     phash_threshold = settings.get("phash_threshold", 2)
+    supersede_smaller = settings.get("supersede_smaller", True)
 
     archive_size = os.path.getsize(archive_path)
     archive_hash = calculate_hash(archive_path)
@@ -420,19 +596,30 @@ def process_archive(archive_path, dest_dir, artist, existing_phashes, settings=N
                         stats["filtered_by_transparency"] += 1
                         continue
 
-                added, _phash, rec = import_single_file(
+                # Apply single-color filter
+                if skip_single_color and lower.endswith((".png", ".jpg", ".jpeg", ".gif", ".webp", ".bmp")):
+                    if is_mostly_single_color(src_path, single_color_threshold, single_color_tolerance):
+                        print(f"[SKIP] Mostly single color: {file}")
+                        stats["filtered_by_single_color"] += 1
+                        continue
+
+                added, _phash, rec, superseded = import_single_file(
                     src_path=src_path,
                     dest_dir=dest_dir,
                     artist=artist,  # still used for auto artist:<name> tag
                     existing_phashes=existing_phashes,
                     commit=False,
-                    phash_threshold=phash_threshold
+                    phash_threshold=phash_threshold,
+                    supersede_smaller=supersede_smaller
                 )
                 if rec is not None:
                     touched_records.append(rec)
                     if added:
                         imported_or_tagged += 1
-                        stats["total_imported"] += 1
+                        if superseded:
+                            stats["total_superseded"] += 1
+                        else:
+                            stats["total_imported"] += 1
                 elif rec is None and _phash is None:
                     stats["filtered_by_duplicate"] += 1
 
@@ -495,11 +682,19 @@ def build_hashed_dest_path(target_dir: str, original_name: str, content_hash: st
         i += 1
 
 
-def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phashes, commit: bool = True, phash_threshold: int = 2):
+def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phashes,
+                       commit: bool = True, phash_threshold: int = 2, supersede_smaller: bool = True):
     """
     Import a single media file. If an equivalent file already exists, return that
     record so callers can tag it (no duplicate import).
-    Returns (added: bool, phash_or_None, record_or_None).
+
+    If a smaller visually-similar image exists and supersede_smaller is True,
+    the smaller image will be replaced with the larger one (preserving tags).
+
+    Also enriches metadata from Gallery-DL sidecar JSON files if present.
+
+    Returns (added: bool, phash_or_None, record_or_None, superseded: bool).
+    The superseded flag indicates if an existing smaller image was replaced.
     """
     original_name = os.path.basename(src_path)
     print(f"[INFO] Processing: {src_path}")
@@ -510,7 +705,9 @@ def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phash
     existing = ImageRecord.query.filter_by(hash=file_hash).first()
     if existing:
         print(f"[SKIP] Duplicate by hash: {original_name}")
-        return (False, None, existing)
+        # Even for duplicates, try to enrich with sidecar metadata
+        _enrich_existing_record(existing, src_path)
+        return (False, None, existing, False)
 
     # Optional info: same name+size (but different content) → we still import with hashed name
     existing_ns = ImageRecord.query.filter_by(filename=original_name, file_size=file_size).first()
@@ -521,12 +718,67 @@ def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phash
     metadata = extract_metadata(src_path)
     if not metadata["width"] or not metadata["height"]:
         print(f"[SKIP] Missing dimension data for {original_name}")
-        return (False, None, None)
+        return (False, None, None, False)
 
     phash = calculate_perceptual_hash(src_path)
-    if phash and phash_threshold > 0 and is_similar_image(phash, metadata["width"], metadata["height"], existing_phashes, threshold=phash_threshold):
-        print(f"[SKIP] {original_name} is visually similar to an existing larger image (threshold={phash_threshold}).")
-        return (False, phash, None)
+
+    # Check for similar images
+    superseded = False
+    if phash and phash_threshold > 0:
+        relationship, similar_id = find_similar_image(
+            phash, metadata["width"], metadata["height"], existing_phashes, threshold=phash_threshold
+        )
+
+        if relationship == "larger_exists":
+            print(f"[SKIP] {original_name} is visually similar to an existing larger image (threshold={phash_threshold}).")
+            return (False, phash, None, False)
+
+        elif relationship == "smaller_exists" and supersede_smaller and similar_id:
+            # Found a smaller version - supersede it
+            old_record = ImageRecord.query.get(similar_id)
+            if old_record:
+                # Enrich metadata from Gallery-DL sidecar JSON if present
+                enriched = _get_enriched_metadata(src_path, metadata)
+                metadata["taken_at"] = enriched.get("taken_at") or metadata["taken_at"]
+
+                # Copy new file to destination
+                target_dir = os.path.join(dest_dir, artist)
+                os.makedirs(target_dir, exist_ok=True)
+                dest_path = build_hashed_dest_path(target_dir, original_name, file_hash)
+                shutil.copy2(src_path, dest_path)
+
+                # Generate new thumbnail
+                try:
+                    if dest_path.lower().endswith((".mp4", ".mov")):
+                        thumb_path = generate_video_thumbnail_mirrored(dest_path)
+                    else:
+                        thumb_path = generate_thumbnail(dest_path)
+                except Exception as e:
+                    print(f"[WARN] Failed to generate thumbnail for {original_name}: {e}")
+                    thumb_path = None
+
+                # Supersede the old record (preserves tags)
+                record = supersede_image(
+                    old_record, dest_path, thumb_path, file_hash, phash, metadata, original_name
+                )
+
+                # Apply any new tags from sidecar
+                _apply_enriched_tags(record, enriched)
+
+                if commit:
+                    db.session.commit()
+
+                # Update existing_phashes list with new dimensions
+                for i, (ph, w, h, img_id) in enumerate(existing_phashes):
+                    if img_id == similar_id:
+                        existing_phashes[i] = (phash, metadata["width"], metadata["height"], img_id)
+                        break
+
+                return (True, phash, record, True)  # superseded=True
+
+    # No similar image found (or supersede disabled) - normal import
+    # Enrich metadata from Gallery-DL sidecar JSON if present
+    enriched = _get_enriched_metadata(src_path, metadata)
 
     # Copy into /images/<artist>/<base>__<hash[:10]><ext>
     target_dir = os.path.join(dest_dir, artist)
@@ -545,6 +797,7 @@ def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phash
         thumb_path = None
 
     # Create DB record (keep display name as original; filepath is content-addressed)
+    # Use enriched taken_at (earliest date wins)
     record = ImageRecord(
         filename=original_name,
         filepath=dest_path,
@@ -556,7 +809,7 @@ def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phash
         height=metadata["height"],
         format=metadata["format"],
         camera_model=metadata["camera_model"],
-        taken_at=metadata["taken_at"],
+        taken_at=enriched.get("taken_at") or metadata["taken_at"],
         imported_at=datetime.utcnow()
     )
 
@@ -571,11 +824,81 @@ def import_single_file(src_path: str, dest_dir: str, artist: str, existing_phash
         if artist_tag not in record.tags:
             record.tags.append(artist_tag)
 
+    # Add tags from Gallery-DL metadata (source:platform, post:platform:artist:id)
+    _apply_enriched_tags(record, enriched)
 
     db.session.add(record)
     if commit:
         db.session.commit()
-    return (True, phash, record)
+    return (True, phash, record, False)  # superseded=False (new import)
+
+
+def _get_enriched_metadata(src_path: str, existing_metadata: dict) -> dict:
+    """
+    Get enriched metadata from Gallery-DL sidecar JSON.
+    Returns empty dict if no sidecar found.
+    """
+    try:
+        from app.utils.metadata_enrichment import enrich_from_sidecar
+        return enrich_from_sidecar(src_path, existing_metadata)
+    except ImportError:
+        return {}
+    except Exception as e:
+        print(f"[WARN] Failed to enrich metadata for {src_path}: {e}")
+        return {}
+
+
+def _apply_enriched_tags(record: ImageRecord, enriched: dict) -> None:
+    """
+    Apply tags from enriched metadata to an ImageRecord.
+    Creates tags if they don't exist.
+    """
+    if not enriched or "tags" not in enriched:
+        return
+
+    for tag_info in enriched.get("tags", []):
+        tag_name = tag_info.get("name")
+        tag_kind = tag_info.get("kind")
+        if not tag_name:
+            continue
+
+        tag = Tag.query.filter_by(name=tag_name).first()
+        if not tag:
+            tag = Tag(name=tag_name, kind=tag_kind)
+            db.session.add(tag)
+            db.session.flush()
+
+        if tag not in record.tags:
+            record.tags.append(tag)
+            print(f"[INFO] Added tag: {tag_name}")
+
+
+def _enrich_existing_record(record: ImageRecord, src_path: str) -> None:
+    """
+    Enrich an existing record with metadata from sidecar JSON.
+    Used when a duplicate is found - we still want to merge metadata.
+
+    - Updates taken_at if sidecar date is earlier
+    - Adds source/post tags if not already present
+    """
+    try:
+        from app.utils.metadata_enrichment import enrich_from_sidecar, resolve_date_conflict
+
+        enriched = enrich_from_sidecar(src_path, {"taken_at": record.taken_at})
+        if not enriched.get("raw_metadata"):
+            return  # No sidecar found
+
+        # Update date if sidecar has an earlier date
+        new_date = resolve_date_conflict(record.taken_at, enriched.get("taken_at"))
+        if new_date != record.taken_at:
+            print(f"[INFO] Updating taken_at for {record.filename}: {record.taken_at} -> {new_date}")
+            record.taken_at = new_date
+
+        # Add any new tags
+        _apply_enriched_tags(record, enriched)
+
+    except Exception as e:
+        print(f"[WARN] Failed to enrich existing record: {e}")
 
 
 # =============================================================================
@@ -593,6 +916,10 @@ def generate_thumbnail(
     Save thumbnails mirrored under /images/thumbs/<...>.
     If prefer_jpeg is False (default), transparent images save as PNG, others as JPEG.
     If prefer_jpeg is True, all thumbs are JPEG with transparency flattened to `jpeg_bg`.
+
+    For images with extreme aspect ratios (very tall like comic strips, or very wide),
+    crops to the center region before thumbnailing to produce better quality previews.
+
     Returns the absolute path to the thumbnail.
     """
     images_root = Path("/images").resolve()
@@ -609,7 +936,27 @@ def generate_thumbnail(
     # Decide output extension/format
     with Image.open(image_path) as img:
         img = ImageOps.exif_transpose(img)  # honor camera rotation
-        img.thumbnail(size)
+
+        # Handle extreme aspect ratios by cropping to a more balanced region
+        # This prevents very tall/wide images from becoming tiny slivers
+        w, h = img.size
+        aspect_ratio = w / h if h > 0 else 1
+
+        # If aspect ratio is extreme (< 0.5 means very tall, > 2.0 means very wide)
+        # crop to a more balanced region before thumbnailing
+        if aspect_ratio < 0.5:
+            # Very tall image (like comic strip) - crop from top portion
+            # Take a region that's closer to square, from the top
+            crop_height = min(h, w * 2)  # At most 2:1 tall
+            img = img.crop((0, 0, w, crop_height))
+        elif aspect_ratio > 2.0:
+            # Very wide image - crop from center
+            crop_width = min(w, h * 2)  # At most 2:1 wide
+            left = (w - crop_width) // 2
+            img = img.crop((left, 0, left + crop_width, h))
+
+        # Use LANCZOS resampling for high-quality downscaling
+        img.thumbnail(size, Image.Resampling.LANCZOS)
 
         has_alpha = _has_alpha(img)
 
@@ -687,24 +1034,69 @@ def calculate_hash(file_path: str) -> str:
     return hash_func.hexdigest()
 
 
-def calculate_perceptual_hash(file_path: str):
+def calculate_perceptual_hash(file_path: str, hash_size: int = 16):
+    """
+    Calculate a perceptual hash for an image.
+
+    Args:
+        file_path: Path to the image file
+        hash_size: Size of the hash grid (default 16 for 256-bit hash)
+                   hash_size=8 gives 64-bit, hash_size=16 gives 256-bit
+
+    Returns:
+        ImageHash object or None if hashing fails (e.g., for videos)
+    """
     try:
         with Image.open(file_path) as img:
-            return imagehash.phash(img)
+            return imagehash.phash(img, hash_size=hash_size)
     except Exception:
         # videos or unreadable images land here (phash not applicable)
         return None
 
 
-def is_similar_image(phash, width: int, height: int, existing_phashes, threshold: int = 2) -> bool:
-    for existing, ew, eh in existing_phashes:
+def find_similar_image(phash, width: int, height: int, existing_phashes, threshold: int = 10):
+    """
+    Find visually similar images and determine relationship.
+
+    Args:
+        phash: Perceptual hash of the new image
+        width: Width of the new image
+        height: Height of the new image
+        existing_phashes: List of (phash, width, height, image_id) tuples for existing images
+        threshold: Maximum Hamming distance to consider images similar
+                   Default is 10 for 256-bit hashes (was 2 for 64-bit)
+
+    Returns:
+        tuple: (relationship, image_id) where relationship is one of:
+            - None: No similar image found
+            - "larger_exists": A larger or equal similar image exists (skip new image)
+            - "smaller_exists": A smaller similar image exists (supersede it)
+        image_id is the ID of the matching image, or None
+    """
+    for existing_phash, ew, eh, image_id in existing_phashes:
         try:
-            distance = phash - existing
-            if distance <= threshold and ew >= width and eh >= height:
-                return True
+            distance = phash - existing_phash
+            if distance <= threshold:
+                # Similar image found - check size relationship
+                if ew >= width and eh >= height:
+                    # Existing is larger or equal - skip new image
+                    return ("larger_exists", image_id)
+                elif width > ew or height > eh:
+                    # New image is larger - supersede the existing one
+                    return ("smaller_exists", image_id)
         except Exception as e:
             print(f"[WARN] Failed pHash comparison: {e}")
-    return False
+    return (None, None)
+
+
+def is_similar_image(phash, width: int, height: int, existing_phashes, threshold: int = 10) -> bool:
+    """
+    Check if an image is visually similar to any existing larger image.
+
+    Legacy wrapper for find_similar_image - returns True only if a larger version exists.
+    """
+    relationship, _ = find_similar_image(phash, width, height, existing_phashes, threshold)
+    return relationship == "larger_exists"
 
 
 def extract_metadata(file_path: str) -> dict:
diff --git a/app/utils/metadata_enrichment.py b/app/utils/metadata_enrichment.py
new file mode 100644
index 0000000..8d40ebd
--- /dev/null
+++ b/app/utils/metadata_enrichment.py
@@ -0,0 +1,346 @@
+# app/utils/metadata_enrichment.py
+"""
+Metadata enrichment from Gallery-DL sidecar JSON files.
+
+This module handles:
+- Detection and parsing of Gallery-DL sidecar .json files
+- Extraction of metadata (dates, tags, post info) from various platforms
+- Tag generation for source tracking (source:platform, post:platform:artist:id)
+- Date conflict resolution (earliest date wins)
+"""
+
+import json
+import logging
+import os
+import re
+from datetime import datetime
+from pathlib import Path
+from typing import Optional
+
+log = logging.getLogger("metadata-enrichment")
+
+
+# =============================================================================
+# Sidecar File Detection
+# =============================================================================
+
+def find_sidecar_json(image_path: str) -> Optional[str]:
+    """
+    Find the Gallery-DL sidecar JSON file for an image.
+
+    Gallery-DL creates JSON files with the UUID portion of the filename.
+    For example:
+        Image: 01_BBEFD45F-8775-4DF9-8BCA-99E6063E3616.jpg
+        JSON:  BBEFD45F-8775-4DF9-8BCA-99E6063E3616.json
+
+    Also checks for direct {filename}.json pattern.
+
+    Returns the path to the sidecar JSON if found, None otherwise.
+    """
+    image_path = Path(image_path)
+    parent_dir = image_path.parent
+    stem = image_path.stem  # filename without extension
+
+    # Pattern 1: Direct {filename}.json (e.g., image.jpg -> image.jpg.json)
+    direct_json = image_path.with_suffix(image_path.suffix + ".json")
+    if direct_json.exists():
+        return str(direct_json)
+
+    # Pattern 2: Extract UUID from filename and look for {uuid}.json
+    # Common patterns: "01_UUID", "UUID", "{num}_{UUID}"
+    uuid_pattern = re.compile(r'([A-F0-9]{8}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{12})', re.IGNORECASE)
+    match = uuid_pattern.search(stem)
+    if match:
+        uuid = match.group(1)
+        uuid_json = parent_dir / f"{uuid}.json"
+        if uuid_json.exists():
+            return str(uuid_json)
+
+    # Pattern 3: Just the stem without prefix numbers
+    # e.g., "01_filename" -> look for "filename.json"
+    stem_no_prefix = re.sub(r'^\d+_', '', stem)
+    if stem_no_prefix != stem:
+        alt_json = parent_dir / f"{stem_no_prefix}.json"
+        if alt_json.exists():
+            return str(alt_json)
+
+    return None
+
+
+def load_sidecar_metadata(json_path: str) -> Optional[dict]:
+    """Load and parse a Gallery-DL sidecar JSON file."""
+    try:
+        with open(json_path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    except (json.JSONDecodeError, IOError) as e:
+        log.warning(f"Failed to load sidecar JSON {json_path}: {e}")
+        return None
+
+
+# =============================================================================
+# Metadata Extraction (Platform-specific)
+# =============================================================================
+
+def extract_platform(metadata: dict) -> Optional[str]:
+    """Extract the platform name from metadata."""
+    # Check common fields
+    if "category" in metadata:
+        return metadata["category"].lower()
+
+    # Infer from URL patterns
+    url = metadata.get("url", "") or metadata.get("post_url", "")
+    if "patreon.com" in url:
+        return "patreon"
+    if "hentai-foundry" in url or "hentaifoundry" in url.lower():
+        return "hentaifoundry"
+    if "subscribestar" in url:
+        return "subscribestar"
+    if "discord.com" in url:
+        return "discord"
+
+    return None
+
+
+def extract_artist(metadata: dict) -> Optional[str]:
+    """Extract the artist/creator name from metadata."""
+    # Try various common fields
+    if "creator" in metadata and isinstance(metadata["creator"], dict):
+        return metadata["creator"].get("vanity") or metadata["creator"].get("full_name")
+
+    if "author_name" in metadata:
+        return metadata["author_name"]
+
+    if "artist" in metadata:
+        return metadata["artist"]
+
+    # For hentaifoundry
+    if "user" in metadata:
+        return metadata["user"]
+
+    return None
+
+
+def extract_post_id(metadata: dict) -> Optional[str]:
+    """Extract the post ID from metadata."""
+    if "id" in metadata:
+        return str(metadata["id"])
+
+    if "post_id" in metadata:
+        return str(metadata["post_id"])
+
+    if "message_id" in metadata:  # Discord
+        return str(metadata["message_id"])
+
+    return None
+
+
+def extract_post_title(metadata: dict) -> Optional[str]:
+    """Extract the post title from metadata."""
+    return metadata.get("title")
+
+
+def extract_date(metadata: dict) -> Optional[datetime]:
+    """
+    Extract the publication/post date from metadata.
+    Tries multiple common date fields and formats.
+    """
+    date_fields = ["published_at", "date", "created_at", "timestamp"]
+
+    for field in date_fields:
+        if field not in metadata:
+            continue
+
+        value = metadata[field]
+        if not value:
+            continue
+
+        # Handle various formats
+        parsed = _parse_date(value)
+        if parsed:
+            return parsed
+
+    return None
+
+
+def _parse_date(value) -> Optional[datetime]:
+    """Parse a date value that could be string, int, or already datetime."""
+    if isinstance(value, datetime):
+        return value
+
+    if isinstance(value, (int, float)):
+        # Unix timestamp
+        try:
+            return datetime.fromtimestamp(value)
+        except (ValueError, OSError):
+            pass
+
+    if isinstance(value, str):
+        # Try common formats
+        formats = [
+            "%Y-%m-%dT%H:%M:%S.%f%z",  # ISO with microseconds and timezone
+            "%Y-%m-%dT%H:%M:%S%z",      # ISO with timezone
+            "%Y-%m-%dT%H:%M:%S.%f",     # ISO with microseconds
+            "%Y-%m-%dT%H:%M:%S",        # ISO basic
+            "%Y-%m-%d %H:%M:%S",        # Space-separated
+            "%Y-%m-%d",                 # Date only
+        ]
+
+        # Handle timezone offset with colon (Python < 3.11 compat)
+        # e.g., "2023-08-01T04:20:02.000+00:00" -> "2023-08-01T04:20:02.000+0000"
+        normalized = re.sub(r'([+-]\d{2}):(\d{2})$', r'\1\2', value)
+
+        for fmt in formats:
+            try:
+                return datetime.strptime(normalized, fmt)
+            except ValueError:
+                continue
+
+        # Try without timezone info
+        # Strip timezone suffix for naive parsing
+        stripped = re.sub(r'[+-]\d{2}:?\d{2}$', '', value)
+        stripped = re.sub(r'Z$', '', stripped)
+        for fmt in formats:
+            try:
+                return datetime.strptime(stripped, fmt)
+            except ValueError:
+                continue
+
+    return None
+
+
+def extract_content_tags(metadata: dict) -> list[str]:
+    """
+    Extract content tags from metadata (not to be confused with DB tags).
+    These are tags the creator applied to the post.
+    """
+    tags = []
+
+    # Direct tags field
+    if "tags" in metadata and isinstance(metadata["tags"], list):
+        tags.extend(metadata["tags"])
+
+    return [str(t) for t in tags if t]
+
+
+# =============================================================================
+# Tag Generation
+# =============================================================================
+
+def generate_source_tags(metadata: dict, artist_override: Optional[str] = None) -> list[dict]:
+    """
+    Generate tags from Gallery-DL metadata.
+
+    Returns a list of tag dictionaries with 'name' and 'kind' keys.
+    Tag format ensures uniqueness:
+    - source:{platform} (kind='source')
+    - post:{platform}:{artist}:{post_id} (kind='post')
+    """
+    tags = []
+
+    platform = extract_platform(metadata)
+    artist = artist_override or extract_artist(metadata)
+    post_id = extract_post_id(metadata)
+
+    # Source platform tag
+    if platform:
+        tags.append({
+            "name": f"source:{platform}",
+            "kind": "source"
+        })
+
+    # Post tag (unique across platform + artist + post_id)
+    if platform and artist and post_id:
+        # Sanitize artist name for tag (lowercase, replace spaces)
+        safe_artist = artist.lower().replace(" ", "_")
+        tags.append({
+            "name": f"post:{platform}:{safe_artist}:{post_id}",
+            "kind": "post"
+        })
+
+    return tags
+
+
+# =============================================================================
+# Date Conflict Resolution
+# =============================================================================
+
+def resolve_date_conflict(existing_date: Optional[datetime], new_date: Optional[datetime]) -> Optional[datetime]:
+    """
+    Resolve date conflicts by keeping the earliest date.
+
+    Args:
+        existing_date: The currently stored date (may be None)
+        new_date: The new date from metadata (may be None)
+
+    Returns:
+        The earliest non-None date, or None if both are None
+    """
+    if existing_date is None:
+        return new_date
+    if new_date is None:
+        return existing_date
+
+    # Return the earlier date
+    return min(existing_date, new_date)
+
+
+# =============================================================================
+# Main Enrichment Function
+# =============================================================================
+
+def enrich_from_sidecar(image_path: str, existing_metadata: Optional[dict] = None) -> dict:
+    """
+    Enrich image metadata from Gallery-DL sidecar JSON.
+
+    Args:
+        image_path: Path to the image file
+        existing_metadata: Optional dict with existing metadata (e.g., from EXIF)
+
+    Returns:
+        Dictionary with enriched metadata:
+        {
+            "platform": str or None,
+            "artist": str or None,
+            "post_id": str or None,
+            "post_title": str or None,
+            "taken_at": datetime or None,
+            "tags": [{"name": str, "kind": str}, ...],
+            "raw_metadata": dict or None (the full sidecar content)
+        }
+    """
+    result = {
+        "platform": None,
+        "artist": None,
+        "post_id": None,
+        "post_title": None,
+        "taken_at": None,
+        "tags": [],
+        "raw_metadata": None,
+    }
+
+    # Find and load sidecar
+    sidecar_path = find_sidecar_json(image_path)
+    if not sidecar_path:
+        return result
+
+    metadata = load_sidecar_metadata(sidecar_path)
+    if not metadata:
+        return result
+
+    result["raw_metadata"] = metadata
+
+    # Extract fields
+    result["platform"] = extract_platform(metadata)
+    result["artist"] = extract_artist(metadata)
+    result["post_id"] = extract_post_id(metadata)
+    result["post_title"] = extract_post_title(metadata)
+
+    # Extract date and resolve conflicts with existing
+    sidecar_date = extract_date(metadata)
+    existing_date = existing_metadata.get("taken_at") if existing_metadata else None
+    result["taken_at"] = resolve_date_conflict(existing_date, sidecar_date)
+
+    # Generate tags
+    result["tags"] = generate_source_tags(metadata, result["artist"])
+
+    return result
diff --git a/app/utils/version_migration.py b/app/utils/version_migration.py
new file mode 100644
index 0000000..0d794af
--- /dev/null
+++ b/app/utils/version_migration.py
@@ -0,0 +1,288 @@
+# app/utils/version_migration.py
+"""
+Version tracking and data migration utilities.
+
+This module handles:
+- Application version tracking via AppSettings
+- Automatic phash recomputation when version changes
+- Settings retrieval/storage from database
+"""
+
+import logging
+import os
+import time
+from typing import Optional
+
+from PIL import Image
+import imagehash
+
+from app import db
+from app.models import AppSettings, ImageRecord
+
+log = logging.getLogger("version-migration")
+
+# =============================================================================
+# Version and pHash Configuration
+# =============================================================================
+
+APP_VERSION = "26.01.19.1"  # Format: YY.MM.DD.iteration
+
+# pHash configuration - 256-bit (hash_size=16 -> 16x16 grid)
+PHASH_HASH_SIZE = 16
+PHASH_BITS = PHASH_HASH_SIZE * PHASH_HASH_SIZE  # 256
+PHASH_THRESHOLD_DEFAULT = 10  # Scaled from 2 (64-bit) to 10 (256-bit)
+
+# Batch size for phash recomputation
+PHASH_RECOMPUTE_BATCH_SIZE = int(os.environ.get("PHASH_RECOMPUTE_BATCH_SIZE", "100"))
+
+
+# =============================================================================
+# Settings Access Functions
+# =============================================================================
+
+def get_setting(key: str, default: Optional[str] = None) -> Optional[str]:
+    """
+    Retrieve a setting value from the database.
+    Returns default if the key doesn't exist.
+    """
+    try:
+        setting = AppSettings.query.filter_by(key=key).first()
+        if setting is not None:
+            return setting.value
+        return default
+    except Exception as e:
+        log.warning(f"Failed to get setting '{key}': {e}")
+        return default
+
+
+def set_setting(key: str, value: str) -> None:
+    """
+    Store a setting value in the database.
+    Creates the key if it doesn't exist, updates if it does.
+    """
+    try:
+        setting = AppSettings.query.filter_by(key=key).first()
+        if setting is None:
+            setting = AppSettings(key=key, value=value)
+            db.session.add(setting)
+        else:
+            setting.value = value
+        db.session.commit()
+    except Exception as e:
+        log.error(f"Failed to set setting '{key}': {e}")
+        db.session.rollback()
+        raise
+
+
+def get_setting_int(key: str, default: int) -> int:
+    """Get a setting as an integer."""
+    val = get_setting(key)
+    if val is None:
+        return default
+    try:
+        return int(val)
+    except ValueError:
+        return default
+
+
+def get_setting_float(key: str, default: float) -> float:
+    """Get a setting as a float."""
+    val = get_setting(key)
+    if val is None:
+        return default
+    try:
+        return float(val)
+    except ValueError:
+        return default
+
+
+def get_setting_bool(key: str, default: bool) -> bool:
+    """Get a setting as a boolean."""
+    val = get_setting(key)
+    if val is None:
+        return default
+    return val.lower() in ("true", "1", "yes")
+
+
+# =============================================================================
+# Import Settings (DB-backed)
+# =============================================================================
+
+def get_import_settings() -> dict:
+    """
+    Load import filter settings from database, with environment variable fallbacks.
+    This replaces the file-based load_import_settings() function.
+    """
+    return {
+        "min_width": get_setting_int("import_min_width", int(os.environ.get("IMPORT_MIN_WIDTH", "0"))),
+        "min_height": get_setting_int("import_min_height", int(os.environ.get("IMPORT_MIN_HEIGHT", "0"))),
+        "skip_transparent": get_setting_bool("import_skip_transparent", os.environ.get("IMPORT_SKIP_TRANSPARENT", "false").lower() == "true"),
+        "transparency_threshold": get_setting_float("import_transparency_threshold", float(os.environ.get("IMPORT_TRANSPARENCY_THRESHOLD", "0.9"))),
+        "phash_threshold": get_setting_int("phash_threshold", PHASH_THRESHOLD_DEFAULT),
+    }
+
+
+# =============================================================================
+# pHash Computation (256-bit)
+# =============================================================================
+
+def calculate_phash_256(file_path: str) -> Optional[imagehash.ImageHash]:
+    """
+    Calculate a 256-bit perceptual hash for an image.
+    Uses hash_size=16 for a 16x16 grid = 256 bits.
+    """
+    try:
+        with Image.open(file_path) as img:
+            return imagehash.phash(img, hash_size=PHASH_HASH_SIZE)
+    except Exception as e:
+        log.debug(f"Could not compute phash for {file_path}: {e}")
+        return None
+
+
+# =============================================================================
+# Version Migration Logic
+# =============================================================================
+
+def recompute_all_phashes() -> dict:
+    """
+    Recompute perceptual hashes for all images using 256-bit hashing.
+    Returns statistics about the operation.
+    """
+    stats = {
+        "total": 0,
+        "updated": 0,
+        "skipped": 0,
+        "failed": 0,
+    }
+
+    log.info("Starting phash recomputation (256-bit)...")
+    t_start = time.time()
+
+    batch_size = PHASH_RECOMPUTE_BATCH_SIZE
+    last_id = 0
+
+    while True:
+        # Fetch batch of images
+        images = (
+            ImageRecord.query
+            .filter(ImageRecord.id > last_id)
+            .order_by(ImageRecord.id.asc())
+            .limit(batch_size)
+            .all()
+        )
+
+        if not images:
+            break
+
+        batch_updated = 0
+        for img in images:
+            stats["total"] += 1
+
+            # Skip videos (no phash)
+            ext = (img.format or "").lower()
+            if ext in ("mp4", "mov") or (img.filepath and img.filepath.lower().endswith((".mp4", ".mov"))):
+                stats["skipped"] += 1
+                continue
+
+            # Skip if file doesn't exist
+            if not img.filepath or not os.path.exists(img.filepath):
+                log.warning(f"File not found for image id={img.id}: {img.filepath}")
+                stats["failed"] += 1
+                continue
+
+            # Compute new phash
+            try:
+                phash = calculate_phash_256(img.filepath)
+                if phash:
+                    img.perceptual_hash = str(phash)
+                    batch_updated += 1
+                    stats["updated"] += 1
+                else:
+                    stats["failed"] += 1
+            except Exception as e:
+                log.warning(f"Failed to compute phash for id={img.id}: {e}")
+                stats["failed"] += 1
+
+        # Commit batch
+        db.session.commit()
+        last_id = images[-1].id
+        log.info(f"Processed batch up to id={last_id}, updated={batch_updated}")
+
+    elapsed = time.time() - t_start
+    log.info(
+        f"pHash recomputation complete in {elapsed:.1f}s: "
+        f"total={stats['total']}, updated={stats['updated']}, "
+        f"skipped={stats['skipped']}, failed={stats['failed']}"
+    )
+
+    return stats
+
+
+def check_and_run_migrations() -> None:
+    """
+    Check the stored app version and run data migrations if needed.
+
+    This function:
+    1. Reads the stored app_version from the database
+    2. Compares it with the current APP_VERSION
+    3. If different, triggers necessary data migrations (e.g., phash recomputation)
+    4. Updates the stored version
+    """
+    log.info(f"Checking app version (current: {APP_VERSION})...")
+
+    stored_version = get_setting("app_version")
+    phash_version = get_setting("phash_version")
+
+    log.info(f"Stored version: {stored_version}, pHash version: {phash_version}")
+
+    # Initialize settings if this is first run
+    if stored_version is None:
+        log.info("First run detected, initializing settings...")
+        _initialize_default_settings()
+        stored_version = "0.0.0.0"  # Force migration on first run
+
+    # Check if phash recomputation is needed
+    needs_phash_recompute = (
+        phash_version is None or
+        phash_version != APP_VERSION or
+        get_setting_int("phash_bits", 64) != PHASH_BITS
+    )
+
+    if needs_phash_recompute:
+        log.info(f"pHash migration needed (stored bits: {get_setting('phash_bits')}, new: {PHASH_BITS})")
+
+        # Update phash configuration
+        set_setting("phash_bits", str(PHASH_BITS))
+        set_setting("phash_hash_size", str(PHASH_HASH_SIZE))
+
+        # Recompute all hashes
+        recompute_all_phashes()
+
+        # Mark phash version as current
+        set_setting("phash_version", APP_VERSION)
+
+    # Update app version
+    if stored_version != APP_VERSION:
+        log.info(f"Updating app version from {stored_version} to {APP_VERSION}")
+        set_setting("app_version", APP_VERSION)
+
+    log.info("Version check complete.")
+
+
+def _initialize_default_settings() -> None:
+    """Initialize default settings on first run."""
+    defaults = {
+        "app_version": APP_VERSION,
+        "phash_version": None,  # Will trigger recomputation
+        "phash_bits": str(PHASH_BITS),
+        "phash_hash_size": str(PHASH_HASH_SIZE),
+        "phash_threshold": str(PHASH_THRESHOLD_DEFAULT),
+        "import_min_width": "0",
+        "import_min_height": "0",
+        "import_skip_transparent": "false",
+        "import_transparency_threshold": "0.9",
+    }
+
+    for key, value in defaults.items():
+        if get_setting(key) is None and value is not None:
+            set_setting(key, value)
diff --git a/entrypoint.sh b/entrypoint.sh
index e9a9f6f..85e97bf 100644
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -20,6 +20,10 @@ if [ "${RUN_DB_MIGRATIONS:-1}" = "1" ]; then
     sleep "$SLEEP_SECS"
     i=$((i+1))
   done
+
+  # Run version check and data migrations (e.g., phash recomputation)
+  echo "Checking app version and running data migrations..."
+  flask version-check
 fi
 
 # --- Start the image import worker exactly once per container ---
diff --git a/migrations/versions/b26011901_add_app_settings_expand_phash.py b/migrations/versions/b26011901_add_app_settings_expand_phash.py
new file mode 100644
index 0000000..98712a7
--- /dev/null
+++ b/migrations/versions/b26011901_add_app_settings_expand_phash.py
@@ -0,0 +1,132 @@
+"""Add app_settings table and expand perceptual_hash to 64 chars for 256-bit hashes
+
+Revision ID: b26011901
+Revises: a46e641430b8
+Create Date: 2026-01-19
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'b26011901'
+down_revision = 'a46e641430b8'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create app_settings table
+    op.create_table(
+        'app_settings',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('key', sa.String(length=64), nullable=False),
+        sa.Column('value', sa.Text(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('key')
+    )
+
+    # Expand perceptual_hash column from 16 to 64 chars
+    bind = op.get_bind()
+    dialect = bind.dialect.name
+
+    if dialect == "sqlite":
+        # SQLite requires table recreation for column type changes.
+        # IMPORTANT: When recreating image_record, we must also recreate
+        # image_tags to preserve foreign key relationships.
+
+        # Step 1: Backup image_tags data
+        op.execute("CREATE TABLE image_tags_backup AS SELECT * FROM image_tags")
+
+        # Step 2: Drop image_tags (it references image_record)
+        op.drop_table("image_tags")
+
+        # Step 3: Recreate image_record with new column size
+        with op.batch_alter_table("image_record", recreate="always") as batch_op:
+            batch_op.alter_column(
+                'perceptual_hash',
+                existing_type=sa.String(length=16),
+                type_=sa.String(length=64),
+                existing_nullable=True
+            )
+
+        # Step 4: Recreate image_tags with proper FK constraints
+        op.create_table(
+            "image_tags",
+            sa.Column("image_id", sa.Integer(), nullable=False),
+            sa.Column("tag_id", sa.Integer(), nullable=False),
+            sa.PrimaryKeyConstraint("image_id", "tag_id"),
+            sa.ForeignKeyConstraint(["image_id"], ["image_record.id"], ondelete="CASCADE"),
+            sa.ForeignKeyConstraint(["tag_id"], ["tag.id"], ondelete="CASCADE"),
+            sa.UniqueConstraint("image_id", "tag_id", name="uq_image_tag"),
+        )
+
+        # Step 5: Restore image_tags data
+        op.execute("INSERT INTO image_tags (image_id, tag_id) SELECT image_id, tag_id FROM image_tags_backup")
+
+        # Step 6: Drop backup table
+        op.drop_table("image_tags_backup")
+    else:
+        # PostgreSQL and others can alter directly
+        op.alter_column(
+            'image_record',
+            'perceptual_hash',
+            existing_type=sa.String(length=16),
+            type_=sa.String(length=64),
+            existing_nullable=True
+        )
+
+
+def downgrade():
+    bind = op.get_bind()
+    dialect = bind.dialect.name
+
+    # Shrink perceptual_hash back to 16 chars (will truncate data!)
+    if dialect == "sqlite":
+        # Same approach as upgrade: backup image_tags, recreate image_record,
+        # then restore image_tags to preserve FK relationships
+
+        # Step 1: Backup image_tags data
+        op.execute("CREATE TABLE image_tags_backup AS SELECT * FROM image_tags")
+
+        # Step 2: Drop image_tags (it references image_record)
+        op.drop_table("image_tags")
+
+        # Step 3: Recreate image_record with old column size
+        with op.batch_alter_table("image_record", recreate="always") as batch_op:
+            batch_op.alter_column(
+                'perceptual_hash',
+                existing_type=sa.String(length=64),
+                type_=sa.String(length=16),
+                existing_nullable=True
+            )
+
+        # Step 4: Recreate image_tags with proper FK constraints
+        op.create_table(
+            "image_tags",
+            sa.Column("image_id", sa.Integer(), nullable=False),
+            sa.Column("tag_id", sa.Integer(), nullable=False),
+            sa.PrimaryKeyConstraint("image_id", "tag_id"),
+            sa.ForeignKeyConstraint(["image_id"], ["image_record.id"], ondelete="CASCADE"),
+            sa.ForeignKeyConstraint(["tag_id"], ["tag.id"], ondelete="CASCADE"),
+            sa.UniqueConstraint("image_id", "tag_id", name="uq_image_tag"),
+        )
+
+        # Step 5: Restore image_tags data
+        op.execute("INSERT INTO image_tags (image_id, tag_id) SELECT image_id, tag_id FROM image_tags_backup")
+
+        # Step 6: Drop backup table
+        op.drop_table("image_tags_backup")
+    else:
+        op.alter_column(
+            'image_record',
+            'perceptual_hash',
+            existing_type=sa.String(length=64),
+            type_=sa.String(length=16),
+            existing_nullable=True
+        )
+
+    # Drop app_settings table
+    op.drop_table('app_settings')