diff --git a/frontend/src/assets/editor-shared.css b/frontend/src/assets/editor-shared.css
index 769f498..80ce3e8 100644
--- a/frontend/src/assets/editor-shared.css
+++ b/frontend/src/assets/editor-shared.css
@@ -532,6 +532,70 @@
   pointer-events: auto;
 }
 
+/* ── Sidebar shared styles ── */
+.sidebar-toggle {
+  display: none;
+  width: 100%;
+  padding: 0.6rem 1rem;
+  background: var(--color-bg-secondary);
+  border: none;
+  border-bottom: 1px solid var(--color-border);
+  font-size: 0.85rem;
+  font-weight: 600;
+  color: var(--color-text-secondary);
+  cursor: pointer;
+  text-align: left;
+  font-family: inherit;
+}
+.sidebar-content {
+  padding: 0.75rem;
+  display: flex;
+  flex-direction: column;
+  gap: 0.65rem;
+}
+.sb-field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.25rem;
+}
+.sb-label {
+  font-size: 0.78rem;
+  font-weight: 600;
+  color: var(--color-text-secondary);
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+}
+.sb-select,
+.sb-input {
+  width: 100%;
+  padding: 0.35rem 0.5rem;
+  border: 1px solid var(--color-input-border);
+  border-radius: var(--radius-sm);
+  background: var(--color-bg-card);
+  color: var(--color-text);
+  font-size: 0.875rem;
+  font-family: inherit;
+  box-sizing: border-box;
+}
+.sb-select:focus,
+.sb-input:focus {
+  outline: none;
+  border-color: var(--color-primary);
+}
+.sb-divider {
+  height: 1px;
+  background: var(--color-border);
+  margin: 0.15rem 0;
+}
+@media (max-width: 720px) {
+  .sidebar-toggle { display: block; }
+  .sidebar-content {
+    display: none;
+    padding: 0.75rem 1rem;
+  }
+  .sidebar-content.sidebar-open { display: flex; }
+}
+
 /* ── Mobile ── */
 @media (max-width: 768px) {
   .editor-body {
diff --git a/frontend/src/assets/viewer-shared.css b/frontend/src/assets/viewer-shared.css
new file mode 100644
index 0000000..d643d08
--- /dev/null
+++ b/frontend/src/assets/viewer-shared.css
@@ -0,0 +1,41 @@
+/* ── Context breadcrumb (shared by NoteViewerView and TaskViewerView) ── */
+.context-bar {
+  display: flex;
+  align-items: center;
+  gap: 0.4rem;
+  flex-wrap: wrap;
+  margin-bottom: 0.6rem;
+}
+.ctx-crumb {
+  display: inline-flex;
+  align-items: center;
+  font-size: 0.8rem;
+  padding: 0.15rem 0.55rem;
+  border-radius: 999px;
+  white-space: nowrap;
+}
+.ctx-crumb-parent {
+  color: var(--color-text-muted);
+  background: var(--color-bg-secondary);
+  border: 1px solid var(--color-border);
+  text-decoration: none;
+}
+.ctx-crumb-parent:hover {
+  color: var(--color-primary);
+  border-color: var(--color-primary);
+}
+.ctx-crumb-project {
+  color: var(--color-primary);
+  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
+  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
+  text-decoration: none;
+  font-weight: 500;
+}
+.ctx-crumb-project:hover {
+  background: color-mix(in srgb, var(--color-primary) 18%, transparent);
+}
+.ctx-crumb-milestone {
+  color: var(--color-text-secondary);
+  background: var(--color-bg-secondary);
+  border: 1px solid var(--color-border);
+}
diff --git a/frontend/src/components/ConfirmDialog.vue b/frontend/src/components/ConfirmDialog.vue
new file mode 100644
index 0000000..aa8400d
--- /dev/null
+++ b/frontend/src/components/ConfirmDialog.vue
@@ -0,0 +1,37 @@
+<script setup lang="ts">
+withDefaults(
+  defineProps<{
+    title: string;
+    message: string;
+    confirmLabel?: string;
+    danger?: boolean;
+  }>(),
+  {
+    confirmLabel: "Delete",
+    danger: true,
+  }
+);
+
+const emit = defineEmits<{
+  confirm: [];
+  cancel: [];
+}>();
+</script>
+
+<template>
+  <teleport to="body">
+    <div class="modal-overlay" @click="emit('cancel')">
+      <div class="modal-card" @click.stop>
+        <h3 class="modal-title">{{ title }}</h3>
+        <p class="modal-message">{{ message }}</p>
+        <div class="modal-actions">
+          <button class="modal-btn" @click="emit('cancel')">Cancel</button>
+          <button
+            :class="['modal-btn', { 'modal-btn-danger': danger }]"
+            @click="emit('confirm')"
+          >{{ confirmLabel }}</button>
+        </div>
+      </div>
+    </div>
+  </teleport>
+</template>
diff --git a/frontend/src/composables/useAutoSave.ts b/frontend/src/composables/useAutoSave.ts
new file mode 100644
index 0000000..1b78bd7
--- /dev/null
+++ b/frontend/src/composables/useAutoSave.ts
@@ -0,0 +1,22 @@
+import { onMounted, onUnmounted } from "vue";
+import type { Ref } from "vue";
+
+export function useAutoSave(
+  dirty: Ref<boolean>,
+  saving: Ref<boolean>,
+  saveFn: () => Promise<void>,
+  intervalMs = 5 * 60 * 1000,
+): void {
+  let timer: ReturnType<typeof setInterval> | null = null;
+
+  onMounted(() => {
+    timer = setInterval(async () => {
+      if (!dirty.value || saving.value) return;
+      await saveFn();
+    }, intervalMs);
+  });
+
+  onUnmounted(() => {
+    if (timer !== null) clearInterval(timer);
+  });
+}
diff --git a/frontend/src/composables/useEditorGuards.ts b/frontend/src/composables/useEditorGuards.ts
new file mode 100644
index 0000000..caff83a
--- /dev/null
+++ b/frontend/src/composables/useEditorGuards.ts
@@ -0,0 +1,33 @@
+import { onMounted, onUnmounted } from "vue";
+import { onBeforeRouteLeave } from "vue-router";
+import type { Ref } from "vue";
+
+export function useEditorGuards(
+  dirty: Ref<boolean>,
+  saveFn: () => void | Promise<void>,
+): void {
+  function onKeydown(e: KeyboardEvent) {
+    if ((e.ctrlKey || e.metaKey) && e.key === "s") {
+      e.preventDefault();
+      saveFn();
+    }
+  }
+
+  function onBeforeUnload(e: BeforeUnloadEvent) {
+    if (dirty.value) e.preventDefault();
+  }
+
+  onMounted(() => {
+    document.addEventListener("keydown", onKeydown);
+    window.addEventListener("beforeunload", onBeforeUnload);
+  });
+
+  onUnmounted(() => {
+    document.removeEventListener("keydown", onKeydown);
+    window.removeEventListener("beforeunload", onBeforeUnload);
+  });
+
+  onBeforeRouteLeave(() => {
+    if (dirty.value) return confirm("You have unsaved changes. Leave anyway?");
+  });
+}
diff --git a/frontend/src/composables/useFloatingAssist.ts b/frontend/src/composables/useFloatingAssist.ts
new file mode 100644
index 0000000..781bc80
--- /dev/null
+++ b/frontend/src/composables/useFloatingAssist.ts
@@ -0,0 +1,34 @@
+import { ref } from "vue";
+
+type Selection = { text: string; start: number; end: number };
+
+export function useFloatingAssist(onRequest: (sel: Selection) => void) {
+  const floatingAssist = ref({ show: false, top: 0, left: 0 });
+  const pendingSelection = ref<Selection | null>(null);
+
+  function onSelectionChange(payload: Selection) {
+    if (payload.text.trim().length > 0) {
+      const sel = window.getSelection();
+      if (sel && sel.rangeCount > 0) {
+        const rect = sel.getRangeAt(0).getBoundingClientRect();
+        floatingAssist.value = {
+          show: true,
+          top: rect.top - 44,
+          left: rect.left + rect.width / 2,
+        };
+        pendingSelection.value = payload;
+      }
+    } else {
+      floatingAssist.value.show = false;
+      pendingSelection.value = null;
+    }
+  }
+
+  function handleInlineAssist() {
+    if (!pendingSelection.value) return;
+    floatingAssist.value.show = false;
+    onRequest(pendingSelection.value);
+  }
+
+  return { floatingAssist, onSelectionChange, handleInlineAssist };
+}
diff --git a/frontend/src/composables/useListKeyboardNavigation.ts b/frontend/src/composables/useListKeyboardNavigation.ts
new file mode 100644
index 0000000..9d4e841
--- /dev/null
+++ b/frontend/src/composables/useListKeyboardNavigation.ts
@@ -0,0 +1,39 @@
+import { ref, onMounted, onUnmounted } from "vue";
+import type { Ref } from "vue";
+
+export function useListKeyboardNavigation<T extends { id: number }>(
+  items: Ref<T[]>,
+  navigateTo: (item: T) => void,
+  rowSelector = ".kb-active-item",
+  enabled?: Ref<boolean>,
+) {
+  const activeIndex = ref(-1);
+
+  function onKeydown(e: KeyboardEvent) {
+    if (enabled && !enabled.value) return;
+    const el = document.activeElement;
+    const tag = el ? (el as HTMLElement).tagName : "";
+    const isInput =
+      tag === "INPUT" || tag === "TEXTAREA" || (el as HTMLElement)?.isContentEditable;
+    if (isInput || e.ctrlKey || e.metaKey || e.altKey) return;
+
+    const count = items.value.length;
+    if (e.key === "j") {
+      e.preventDefault();
+      activeIndex.value = Math.min(activeIndex.value + 1, count - 1);
+      document.querySelector(rowSelector)?.scrollIntoView({ block: "nearest" });
+    } else if (e.key === "k") {
+      e.preventDefault();
+      activeIndex.value = Math.max(activeIndex.value - 1, 0);
+      document.querySelector(rowSelector)?.scrollIntoView({ block: "nearest" });
+    } else if (e.key === "Enter" && activeIndex.value >= 0) {
+      const item = items.value[activeIndex.value];
+      if (item) navigateTo(item);
+    }
+  }
+
+  onMounted(() => document.addEventListener("keydown", onKeydown));
+  onUnmounted(() => document.removeEventListener("keydown", onKeydown));
+
+  return { activeIndex };
+}
diff --git a/frontend/src/composables/useTagSuggestions.ts b/frontend/src/composables/useTagSuggestions.ts
new file mode 100644
index 0000000..9c48c64
--- /dev/null
+++ b/frontend/src/composables/useTagSuggestions.ts
@@ -0,0 +1,58 @@
+import { ref } from "vue";
+import type { Ref } from "vue";
+import { apiPost } from "@/api/client";
+import { useToastStore } from "@/stores/toast";
+
+export function useTagSuggestions(
+  title: Ref<string>,
+  body: Ref<string>,
+  tags: Ref<string[]>,
+  markDirty: () => void,
+) {
+  const suggestedTags = ref<string[]>([]);
+  const appliedTags = ref<Set<string>>(new Set());
+  const suggestingTags = ref(false);
+
+  async function fetchTagSuggestions() {
+    if (suggestingTags.value) return;
+    suggestingTags.value = true;
+    suggestedTags.value = [];
+    appliedTags.value = new Set();
+    const toast = useToastStore();
+    try {
+      const res = await apiPost<{ suggested_tags: string[] }>("/api/notes/suggest-tags", {
+        title: title.value,
+        body: body.value,
+        current_tags: tags.value,
+      });
+      suggestedTags.value = res.suggested_tags;
+    } catch {
+      toast.show("Failed to get tag suggestions", "error");
+    } finally {
+      suggestingTags.value = false;
+    }
+  }
+
+  function applyTagSuggestion(tag: string) {
+    if (appliedTags.value.has(tag)) return;
+    if (!tags.value.includes(tag)) {
+      tags.value = [...tags.value, tag];
+    }
+    appliedTags.value.add(tag);
+    markDirty();
+  }
+
+  function dismissTagSuggestions() {
+    suggestedTags.value = [];
+    appliedTags.value = new Set();
+  }
+
+  return {
+    suggestedTags,
+    appliedTags,
+    suggestingTags,
+    fetchTagSuggestions,
+    applyTagSuggestion,
+    dismissTagSuggestions,
+  };
+}
diff --git a/frontend/src/views/NoteEditorView.vue b/frontend/src/views/NoteEditorView.vue
index 3b7cd09..6103275 100644
--- a/frontend/src/views/NoteEditorView.vue
+++ b/frontend/src/views/NoteEditorView.vue
@@ -1,11 +1,15 @@
 <script setup lang="ts">
 import { ref, onMounted, onUnmounted, computed, nextTick, watch } from "vue";
-import { useRoute, useRouter, onBeforeRouteLeave } from "vue-router";
+import { useRoute, useRouter } from "vue-router";
 import { useNotesStore } from "@/stores/notes";
 import { useToastStore } from "@/stores/toast";
 import { renderMarkdown } from "@/utils/markdown";
 import { useAssist, type NoteDraft } from "@/composables/useAssist";
-import { apiPost, apiGet } from "@/api/client";
+import { useAutoSave } from "@/composables/useAutoSave";
+import { useEditorGuards } from "@/composables/useEditorGuards";
+import { useTagSuggestions } from "@/composables/useTagSuggestions";
+import { useFloatingAssist } from "@/composables/useFloatingAssist";
+import { apiGet, apiPost } from "@/api/client";
 import type { Editor } from "@tiptap/vue-3";
 import MarkdownToolbar from "@/components/MarkdownToolbar.vue";
 import TiptapEditor from "@/components/TiptapEditor.vue";
@@ -14,6 +18,7 @@ import ProjectSelector from "@/components/ProjectSelector.vue";
 import MilestoneSelector from "@/components/MilestoneSelector.vue";
 import DiffView from "@/components/DiffView.vue";
 import HistoryPanel from "@/components/HistoryPanel.vue";
+import ConfirmDialog from "@/components/ConfirmDialog.vue";
 
 const route = useRoute();
 const router = useRouter();
@@ -84,31 +89,14 @@ const scopeSelectValue = computed({
 });
 
 // Floating inline assist button
-const floatingAssist = ref({ show: false, top: 0, left: 0 });
-const pendingSelection = ref<{ start: number; end: number } | null>(null);
 const instructionRef = ref<HTMLTextAreaElement | null>(null);
-
-function onSelectionChange(payload: { text: string; start: number; end: number }) {
-  if (payload.text.trim().length > 0) {
-    const sel = window.getSelection();
-    if (sel && sel.rangeCount > 0) {
-      const rect = sel.getRangeAt(0).getBoundingClientRect();
-      floatingAssist.value = { show: true, top: rect.top - 44, left: rect.left + rect.width / 2 };
-      pendingSelection.value = { start: payload.start, end: payload.end };
-    }
-  } else {
-    floatingAssist.value.show = false;
-    pendingSelection.value = null;
+const { floatingAssist, onSelectionChange, handleInlineAssist } = useFloatingAssist(
+  ({ start, end }) => {
+    assist.scopeMode.value = 'section';
+    assist.selectTextRange(start, end);
+    nextTick(() => instructionRef.value?.focus());
   }
-}
-
-function handleInlineAssist() {
-  if (!pendingSelection.value) return;
-  assist.scopeMode.value = 'section';
-  assist.selectTextRange(pendingSelection.value.start, pendingSelection.value.end);
-  floatingAssist.value.show = false;
-  nextTick(() => instructionRef.value?.focus());
-}
+);
 
 function handleAssistAccept() {
   const newBody = assist.accept();
@@ -118,42 +106,8 @@ function handleAssistAccept() {
 }
 
 // Tag suggestions
-const suggestedTags = ref<string[]>([]);
-const appliedTags = ref<Set<string>>(new Set());
-const suggestingTags = ref(false);
-
-async function fetchTagSuggestions() {
-  if (suggestingTags.value) return;
-  suggestingTags.value = true;
-  suggestedTags.value = [];
-  appliedTags.value = new Set();
-  try {
-    const res = await apiPost<{ suggested_tags: string[] }>("/api/notes/suggest-tags", {
-      title: title.value,
-      body: body.value,
-      current_tags: tags.value,
-    });
-    suggestedTags.value = res.suggested_tags;
-  } catch {
-    toast.show("Failed to get tag suggestions", "error");
-  } finally {
-    suggestingTags.value = false;
-  }
-}
-
-function applyTagSuggestion(tag: string) {
-  if (appliedTags.value.has(tag)) return;
-  if (!tags.value.includes(tag)) {
-    tags.value = [...tags.value, tag];
-  }
-  appliedTags.value.add(tag);
-  markDirty();
-}
-
-function dismissTagSuggestions() {
-  suggestedTags.value = [];
-  appliedTags.value = new Set();
-}
+const { suggestedTags, appliedTags, suggestingTags, fetchTagSuggestions, applyTagSuggestion, dismissTagSuggestions } =
+  useTagSuggestions(title, body, tags, markDirty);
 
 // ── Link Suggestions ────────────────────────────────────────────────────────
 
@@ -331,10 +285,8 @@ async function confirmDelete() {
 }
 
 // Auto-save every 5 minutes
-let autoSaveTimer: ReturnType<typeof setInterval> | null = null;
-
-async function autoSave() {
-  if (!isEditing.value || !dirty.value || saving.value) return;
+async function doAutoSave() {
+  if (!isEditing.value || saving.value) return;
   saving.value = true;
   try {
     await store.updateNote(noteId.value!, {
@@ -354,29 +306,8 @@ async function autoSave() {
     saving.value = false;
   }
 }
-
-onMounted(() => { autoSaveTimer = setInterval(autoSave, 5 * 60 * 1000); });
-onUnmounted(() => { if (autoSaveTimer !== null) clearInterval(autoSaveTimer); });
-
-function onKeydown(e: KeyboardEvent) {
-  if ((e.ctrlKey || e.metaKey) && e.key === "s") {
-    e.preventDefault();
-    save();
-  }
-}
-
-onMounted(() => document.addEventListener("keydown", onKeydown));
-onUnmounted(() => document.removeEventListener("keydown", onKeydown));
-
-onBeforeRouteLeave(() => {
-  if (dirty.value) return confirm("You have unsaved changes. Leave anyway?");
-});
-
-function onBeforeUnload(e: BeforeUnloadEvent) {
-  if (dirty.value) e.preventDefault();
-}
-onMounted(() => window.addEventListener("beforeunload", onBeforeUnload));
-onUnmounted(() => window.removeEventListener("beforeunload", onBeforeUnload));
+useAutoSave(dirty, saving, doAutoSave);
+useEditorGuards(dirty, save);
 
 // Close any in-flight assist SSE stream when navigating away
 onUnmounted(() => assist.clearSelection());
@@ -595,18 +526,13 @@ onUnmounted(() => assist.clearSelection());
     />
 
     <!-- Delete confirmation -->
-    <teleport to="body">
-      <div v-if="showDeleteConfirm" class="modal-overlay" @click="showDeleteConfirm = false">
-        <div class="modal-card" @click.stop>
-          <h3 class="modal-title">Delete Note</h3>
-          <p class="modal-message">Are you sure you want to delete this note? This cannot be undone.</p>
-          <div class="modal-actions">
-            <button class="modal-btn" @click="showDeleteConfirm = false">Cancel</button>
-            <button class="modal-btn modal-btn-danger" @click="confirmDelete">Delete</button>
-          </div>
-        </div>
-      </div>
-    </teleport>
+    <ConfirmDialog
+      v-if="showDeleteConfirm"
+      title="Delete Note"
+      message="Are you sure you want to delete this note? This cannot be undone."
+      @confirm="confirmDelete"
+      @cancel="showDeleteConfirm = false"
+    />
   </main>
 </template>
 
@@ -675,61 +601,6 @@ onUnmounted(() => assist.clearSelection());
   flex-direction: column;
 }
 
-/* Mobile accordion toggle (hidden on desktop) */
-.sidebar-toggle {
-  display: none;
-  width: 100%;
-  padding: 0.6rem 1rem;
-  background: var(--color-bg-secondary);
-  border: none;
-  border-bottom: 1px solid var(--color-border);
-  font-size: 0.85rem;
-  font-weight: 600;
-  color: var(--color-text-secondary);
-  cursor: pointer;
-  text-align: left;
-  font-family: inherit;
-}
-
-.sidebar-content {
-  padding: 0.75rem;
-  display: flex;
-  flex-direction: column;
-  gap: 0.65rem;
-}
-
-/* Sidebar field layout */
-.sb-field {
-  display: flex;
-  flex-direction: column;
-  gap: 0.25rem;
-}
-.sb-label {
-  font-size: 0.78rem;
-  font-weight: 600;
-  color: var(--color-text-secondary);
-  text-transform: uppercase;
-  letter-spacing: 0.04em;
-}
-.sb-select {
-  width: 100%;
-  padding: 0.35rem 0.5rem;
-  border: 1px solid var(--color-input-border);
-  border-radius: var(--radius-sm);
-  background: var(--color-bg-card);
-  color: var(--color-text);
-  font-size: 0.875rem;
-  font-family: inherit;
-  box-sizing: border-box;
-}
-.sb-select:focus { outline: none; border-color: var(--color-primary); }
-
-.sb-divider {
-  height: 1px;
-  background: var(--color-border);
-  margin: 0.15rem 0;
-}
-
 /* Tag suggest row inside sidebar */
 .tag-suggest-row {
   display: flex;
@@ -841,11 +712,5 @@ onUnmounted(() => assist.clearSelection());
     border-top: 1px solid var(--color-border);
     overflow-y: visible;
   }
-  .sidebar-toggle { display: block; }
-  .sidebar-content {
-    display: none;
-    padding: 0.75rem 1rem;
-  }
-  .sidebar-content.sidebar-open { display: flex; }
 }
 </style>
diff --git a/frontend/src/views/NoteViewerView.vue b/frontend/src/views/NoteViewerView.vue
index de254d0..a7b0119 100644
--- a/frontend/src/views/NoteViewerView.vue
+++ b/frontend/src/views/NoteViewerView.vue
@@ -229,6 +229,7 @@ async function convertToTask() {
   </div>
 </template>
 
+<style src="@/assets/viewer-shared.css" />
 <style scoped>
 .viewer-layout {
   display: flex;
@@ -294,48 +295,6 @@ async function convertToTask() {
   cursor: default;
 }
 
-/* Context breadcrumb */
-.context-bar {
-  display: flex;
-  align-items: center;
-  gap: 0.4rem;
-  flex-wrap: wrap;
-  margin-bottom: 0.6rem;
-}
-.ctx-crumb {
-  display: inline-flex;
-  align-items: center;
-  font-size: 0.8rem;
-  padding: 0.15rem 0.55rem;
-  border-radius: 999px;
-  white-space: nowrap;
-}
-.ctx-crumb-parent {
-  color: var(--color-text-muted);
-  background: var(--color-bg-secondary);
-  border: 1px solid var(--color-border);
-  text-decoration: none;
-}
-.ctx-crumb-parent:hover {
-  color: var(--color-primary);
-  border-color: var(--color-primary);
-}
-.ctx-crumb-project {
-  color: var(--color-primary);
-  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
-  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
-  text-decoration: none;
-  font-weight: 500;
-}
-.ctx-crumb-project:hover {
-  background: color-mix(in srgb, var(--color-primary) 18%, transparent);
-}
-.ctx-crumb-milestone {
-  color: var(--color-text-secondary);
-  background: var(--color-bg-secondary);
-  border: 1px solid var(--color-border);
-}
-
 .meta {
   font-size: 0.85rem;
   color: var(--color-text-muted);
diff --git a/frontend/src/views/NotesListView.vue b/frontend/src/views/NotesListView.vue
index 4330b40..98f2623 100644
--- a/frontend/src/views/NotesListView.vue
+++ b/frontend/src/views/NotesListView.vue
@@ -1,7 +1,8 @@
 <script setup lang="ts">
-import { ref, onMounted, onUnmounted, watch } from "vue";
+import { ref, computed, onMounted, onUnmounted, watch } from "vue";
 import { useRoute, useRouter } from "vue-router";
 import { useNotesStore } from "@/stores/notes";
+import { useListKeyboardNavigation } from "@/composables/useListKeyboardNavigation";
 import SearchBar from "@/components/SearchBar.vue";
 import NoteCard from "@/components/NoteCard.vue";
 import TagPill from "@/components/TagPill.vue";
@@ -14,36 +15,15 @@ const router = useRouter();
 const store = useNotesStore();
 
 const searchBarRef = ref<{ focus: () => void } | null>(null);
-const activeIndex = ref(-1);
 
 function onFocusSearch() {
   searchBarRef.value?.focus();
 }
 
-function onKeydown(e: KeyboardEvent) {
-  const el = document.activeElement;
-  const tag = el ? (el as HTMLElement).tagName : "";
-  const isInput = tag === "INPUT" || tag === "TEXTAREA" || (el as HTMLElement)?.isContentEditable;
-  if (isInput || e.ctrlKey || e.metaKey || e.altKey) return;
-  const count = store.notes.length;
-  if (e.key === "j") {
-    e.preventDefault();
-    activeIndex.value = Math.min(activeIndex.value + 1, count - 1);
-    scrollActiveIntoView();
-  } else if (e.key === "k") {
-    e.preventDefault();
-    activeIndex.value = Math.max(activeIndex.value - 1, 0);
-    scrollActiveIntoView();
-  } else if (e.key === "Enter" && activeIndex.value >= 0) {
-    const note = store.notes[activeIndex.value];
-    if (note) router.push(`/notes/${note.id}`);
-  }
-}
-
-function scrollActiveIntoView() {
-  const el = document.querySelector(".kb-active-item");
-  if (el) el.scrollIntoView({ block: "nearest" });
-}
+const { activeIndex } = useListKeyboardNavigation(
+  computed(() => store.notes),
+  (note) => router.push(`/notes/${note.id}`),
+);
 
 const viewMode = ref<ViewMode>(
   (localStorage.getItem("fabled-notes-view-mode") as ViewMode) ?? "grid"
@@ -63,12 +43,10 @@ onMounted(() => {
     store.refresh();
   }
   document.addEventListener("shortcut:focus-search", onFocusSearch);
-  document.addEventListener("keydown", onKeydown);
 });
 
 onUnmounted(() => {
   document.removeEventListener("shortcut:focus-search", onFocusSearch);
-  document.removeEventListener("keydown", onKeydown);
 });
 
 watch(
diff --git a/frontend/src/views/TaskEditorView.vue b/frontend/src/views/TaskEditorView.vue
index 500f400..22d2550 100644
--- a/frontend/src/views/TaskEditorView.vue
+++ b/frontend/src/views/TaskEditorView.vue
@@ -1,11 +1,15 @@
 <script setup lang="ts">
-import { ref, onMounted, onUnmounted, computed, nextTick } from "vue";
-import { useRoute, useRouter, onBeforeRouteLeave } from "vue-router";
+import { ref, onMounted, computed, nextTick } from "vue";
+import { useRoute, useRouter } from "vue-router";
 import { useTasksStore } from "@/stores/tasks";
 import { useNotesStore } from "@/stores/notes";
 import { useToastStore } from "@/stores/toast";
 import { renderMarkdown } from "@/utils/markdown";
 import { useAssist } from "@/composables/useAssist";
+import { useAutoSave } from "@/composables/useAutoSave";
+import { useEditorGuards } from "@/composables/useEditorGuards";
+import { useTagSuggestions } from "@/composables/useTagSuggestions";
+import { useFloatingAssist } from "@/composables/useFloatingAssist";
 import { apiPost, apiGet, apiPatch } from "@/api/client";
 import type { TaskStatus, TaskPriority } from "@/types/task";
 import type { Editor } from "@tiptap/vue-3";
@@ -16,6 +20,7 @@ import ProjectSelector from "@/components/ProjectSelector.vue";
 import MilestoneSelector from "@/components/MilestoneSelector.vue";
 import TaskLogSection from "@/components/TaskLogSection.vue";
 import InlineAssistPanel from "@/components/InlineAssistPanel.vue";
+import ConfirmDialog from "@/components/ConfirmDialog.vue";
 
 const route = useRoute();
 const router = useRouter();
@@ -126,32 +131,15 @@ function toggleAssist() {
 }
 
 // Floating inline assist button
-const floatingAssist = ref({ show: false, top: 0, left: 0 });
-const pendingSelection = ref<{ start: number; end: number } | null>(null);
 const instructionRef = ref<HTMLTextAreaElement | null>(null);
-
-function onSelectionChange(payload: { text: string; start: number; end: number }) {
-  if (payload.text.trim().length > 0) {
-    const sel = window.getSelection();
-    if (sel && sel.rangeCount > 0) {
-      const rect = sel.getRangeAt(0).getBoundingClientRect();
-      floatingAssist.value = { show: true, top: rect.top - 44, left: rect.left + rect.width / 2 };
-      pendingSelection.value = { start: payload.start, end: payload.end };
-    }
-  } else {
-    floatingAssist.value.show = false;
-    pendingSelection.value = null;
+const { floatingAssist, onSelectionChange, handleInlineAssist } = useFloatingAssist(
+  ({ start, end }) => {
+    assist.selectTextRange(start, end);
+    assistOpen.value = true;
+    localStorage.setItem(ASSIST_KEY, 'true');
+    nextTick(() => instructionRef.value?.focus());
   }
-}
-
-function handleInlineAssist() {
-  if (!pendingSelection.value) return;
-  assist.selectTextRange(pendingSelection.value.start, pendingSelection.value.end);
-  assistOpen.value = true;
-  localStorage.setItem(ASSIST_KEY, 'true');
-  floatingAssist.value.show = false;
-  nextTick(() => instructionRef.value?.focus());
-}
+);
 
 function handleAssistAccept() {
   const newBody = assist.accept();
@@ -168,42 +156,8 @@ function truncateTarget(text: string, max = 60): string {
 }
 
 // Tag suggestions
-const suggestedTags = ref<string[]>([]);
-const appliedTags = ref<Set<string>>(new Set());
-const suggestingTags = ref(false);
-
-async function fetchTagSuggestions() {
-  if (suggestingTags.value) return;
-  suggestingTags.value = true;
-  suggestedTags.value = [];
-  appliedTags.value = new Set();
-  try {
-    const res = await apiPost<{ suggested_tags: string[] }>("/api/notes/suggest-tags", {
-      title: title.value,
-      body: body.value,
-      current_tags: tags.value,
-    });
-    suggestedTags.value = res.suggested_tags;
-  } catch {
-    toast.show("Failed to get tag suggestions", "error");
-  } finally {
-    suggestingTags.value = false;
-  }
-}
-
-function applyTagSuggestion(tag: string) {
-  if (appliedTags.value.has(tag)) return;
-  if (!tags.value.includes(tag)) {
-    tags.value = [...tags.value, tag];
-  }
-  appliedTags.value.add(tag);
-  markDirty();
-}
-
-function dismissTagSuggestions() {
-  suggestedTags.value = [];
-  appliedTags.value = new Set();
-}
+const { suggestedTags, appliedTags, suggestingTags, fetchTagSuggestions, applyTagSuggestion, dismissTagSuggestions } =
+  useTagSuggestions(title, body, tags, markDirty);
 
 let savedTitle = "";
 let savedBody = "";
@@ -383,10 +337,8 @@ async function confirmDelete() {
 }
 
 // Auto-save every 5 minutes when editing an existing task
-let autoSaveTimer: ReturnType<typeof setInterval> | null = null;
-
-async function autoSave() {
-  if (!isEditing.value || !dirty.value || saving.value) return;
+async function doAutoSave() {
+  if (!isEditing.value || saving.value) return;
   saving.value = true;
   try {
     await store.updateTask(taskId.value!, {
@@ -417,33 +369,8 @@ async function autoSave() {
     saving.value = false;
   }
 }
-
-onMounted(() => { autoSaveTimer = setInterval(autoSave, 5 * 60 * 1000); });
-onUnmounted(() => { if (autoSaveTimer !== null) clearInterval(autoSaveTimer); });
-
-function onKeydown(e: KeyboardEvent) {
-  if ((e.ctrlKey || e.metaKey) && e.key === "s") {
-    e.preventDefault();
-    save();
-  }
-}
-
-onMounted(() => document.addEventListener("keydown", onKeydown));
-onUnmounted(() => document.removeEventListener("keydown", onKeydown));
-
-onBeforeRouteLeave(() => {
-  if (dirty.value) {
-    return confirm("You have unsaved changes. Leave anyway?");
-  }
-});
-
-function onBeforeUnload(e: BeforeUnloadEvent) {
-  if (dirty.value) {
-    e.preventDefault();
-  }
-}
-onMounted(() => window.addEventListener("beforeunload", onBeforeUnload));
-onUnmounted(() => window.removeEventListener("beforeunload", onBeforeUnload));
+useAutoSave(dirty, saving, doAutoSave);
+useEditorGuards(dirty, save);
 </script>
 
 <template>
@@ -710,18 +637,13 @@ onUnmounted(() => window.removeEventListener("beforeunload", onBeforeUnload));
     </teleport>
 
     <!-- Delete confirmation -->
-    <teleport to="body">
-      <div v-if="showDeleteConfirm" class="modal-overlay" @click="showDeleteConfirm = false">
-        <div class="modal-card" @click.stop>
-          <h3 class="modal-title">Delete Task</h3>
-          <p class="modal-message">Are you sure you want to delete this task? This cannot be undone.</p>
-          <div class="modal-actions">
-            <button class="modal-btn" @click="showDeleteConfirm = false">Cancel</button>
-            <button class="modal-btn modal-btn-danger" @click="confirmDelete">Delete</button>
-          </div>
-        </div>
-      </div>
-    </teleport>
+    <ConfirmDialog
+      v-if="showDeleteConfirm"
+      title="Delete Task"
+      message="Are you sure you want to delete this task? This cannot be undone."
+      @confirm="confirmDelete"
+      @cancel="showDeleteConfirm = false"
+    />
   </main>
 </template>
 
@@ -777,66 +699,6 @@ onUnmounted(() => window.removeEventListener("beforeunload", onBeforeUnload));
   flex-direction: column;
 }
 
-/* Mobile accordion toggle (hidden on desktop) */
-.sidebar-toggle {
-  display: none;
-  width: 100%;
-  padding: 0.6rem 1rem;
-  background: var(--color-bg-secondary);
-  border: none;
-  border-bottom: 1px solid var(--color-border);
-  font-size: 0.85rem;
-  font-weight: 600;
-  color: var(--color-text-secondary);
-  cursor: pointer;
-  text-align: left;
-  font-family: inherit;
-}
-
-.sidebar-content {
-  padding: 0.75rem;
-  display: flex;
-  flex-direction: column;
-  gap: 0.65rem;
-}
-
-/* Sidebar field layout */
-.sb-field {
-  display: flex;
-  flex-direction: column;
-  gap: 0.25rem;
-}
-.sb-label {
-  font-size: 0.78rem;
-  font-weight: 600;
-  color: var(--color-text-secondary);
-  text-transform: uppercase;
-  letter-spacing: 0.04em;
-}
-.sb-select,
-.sb-input {
-  width: 100%;
-  padding: 0.35rem 0.5rem;
-  border: 1px solid var(--color-input-border);
-  border-radius: var(--radius-sm);
-  background: var(--color-bg-card);
-  color: var(--color-text);
-  font-size: 0.875rem;
-  font-family: inherit;
-  box-sizing: border-box;
-}
-.sb-select:focus,
-.sb-input:focus {
-  outline: none;
-  border-color: var(--color-primary);
-}
-
-.sb-divider {
-  height: 1px;
-  background: var(--color-border);
-  margin: 0.15rem 0;
-}
-
 /* Parent task search */
 .parent-search-wrapper { position: relative; }
 .parent-input-row { display: flex; align-items: center; gap: 0.25rem; }
@@ -985,11 +847,5 @@ onUnmounted(() => window.removeEventListener("beforeunload", onBeforeUnload));
     border-top: 1px solid var(--color-border);
     overflow-y: visible;
   }
-  .sidebar-toggle { display: block; }
-  .sidebar-content {
-    display: none;
-    padding: 0.75rem 1rem;
-  }
-  .sidebar-content.sidebar-open { display: flex; }
 }
 </style>
\ No newline at end of file
diff --git a/frontend/src/views/TaskViewerView.vue b/frontend/src/views/TaskViewerView.vue
index 4494218..4810b5e 100644
--- a/frontend/src/views/TaskViewerView.vue
+++ b/frontend/src/views/TaskViewerView.vue
@@ -315,6 +315,7 @@ const subTaskProgress = computed(() => {
   </div>
 </template>
 
+<style src="@/assets/viewer-shared.css" />
 <style scoped>
 .viewer-layout {
   display: flex;
@@ -380,48 +381,6 @@ const subTaskProgress = computed(() => {
   cursor: default;
 }
 
-/* Context breadcrumb */
-.context-bar {
-  display: flex;
-  align-items: center;
-  gap: 0.4rem;
-  flex-wrap: wrap;
-  margin-bottom: 0.6rem;
-}
-.ctx-crumb {
-  display: inline-flex;
-  align-items: center;
-  font-size: 0.8rem;
-  padding: 0.15rem 0.55rem;
-  border-radius: 999px;
-  white-space: nowrap;
-}
-.ctx-crumb-parent {
-  color: var(--color-text-muted);
-  background: var(--color-bg-secondary);
-  border: 1px solid var(--color-border);
-  text-decoration: none;
-}
-.ctx-crumb-parent:hover {
-  color: var(--color-primary);
-  border-color: var(--color-primary);
-}
-.ctx-crumb-project {
-  color: var(--color-primary);
-  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
-  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
-  text-decoration: none;
-  font-weight: 500;
-}
-.ctx-crumb-project:hover {
-  background: color-mix(in srgb, var(--color-primary) 18%, transparent);
-}
-.ctx-crumb-milestone {
-  color: var(--color-text-secondary);
-  background: var(--color-bg-secondary);
-  border: 1px solid var(--color-border);
-}
-
 .meta {
   font-size: 0.85rem;
   color: var(--color-text-muted);
diff --git a/frontend/src/views/TasksListView.vue b/frontend/src/views/TasksListView.vue
index eeefa70..041a74b 100644
--- a/frontend/src/views/TasksListView.vue
+++ b/frontend/src/views/TasksListView.vue
@@ -4,6 +4,7 @@ import { useRoute, useRouter } from "vue-router";
 import { useTasksStore } from "@/stores/tasks";
 import type { Task, TaskStatus } from "@/types/task";
 import { apiGet } from "@/api/client";
+import { useListKeyboardNavigation } from "@/composables/useListKeyboardNavigation";
 import SearchBar from "@/components/SearchBar.vue";
 import TaskCard from "@/components/TaskCard.vue";
 import TagPill from "@/components/TagPill.vue";
@@ -16,33 +17,11 @@ const router = useRouter();
 const store = useTasksStore();
 
 const searchBarRef = ref<{ focus: () => void } | null>(null);
-const activeIndex = ref(-1);
 
 function onFocusSearch() {
   searchBarRef.value?.focus();
 }
 
-function onKeydown(e: KeyboardEvent) {
-  if (viewMode.value !== "flat") return;
-  const el = document.activeElement;
-  const tag = el ? (el as HTMLElement).tagName : "";
-  const isInput = tag === "INPUT" || tag === "TEXTAREA" || (el as HTMLElement)?.isContentEditable;
-  if (isInput || e.ctrlKey || e.metaKey || e.altKey) return;
-  const count = store.tasks.length;
-  if (e.key === "j") {
-    e.preventDefault();
-    activeIndex.value = Math.min(activeIndex.value + 1, count - 1);
-    document.querySelector(".kb-active-item")?.scrollIntoView({ block: "nearest" });
-  } else if (e.key === "k") {
-    e.preventDefault();
-    activeIndex.value = Math.max(activeIndex.value - 1, 0);
-    document.querySelector(".kb-active-item")?.scrollIntoView({ block: "nearest" });
-  } else if (e.key === "Enter" && activeIndex.value >= 0) {
-    const task = store.tasks[activeIndex.value];
-    if (task) router.push(`/tasks/${task.id}`);
-  }
-}
-
 const viewMode = ref<ViewMode>(
   (localStorage.getItem("fabled-tasks-view-mode") as ViewMode) ?? "flat"
 );
@@ -60,6 +39,14 @@ function setViewMode(mode: ViewMode) {
   store.refresh();
 }
 
+const isFlat = computed(() => viewMode.value === "flat");
+const { activeIndex } = useListKeyboardNavigation(
+  computed(() => store.tasks),
+  (task) => router.push(`/tasks/${task.id}`),
+  ".kb-active-item",
+  isFlat,
+);
+
 // Project map for group labels and task breadcrumbs
 const projectMap = ref<Map<number, string>>(new Map());
 
@@ -119,12 +106,10 @@ onMounted(async () => {
   }
   await Promise.all([store.refresh(), loadProjects()]);
   document.addEventListener("shortcut:focus-search", onFocusSearch);
-  document.addEventListener("keydown", onKeydown);
 });
 
 onUnmounted(() => {
   document.removeEventListener("shortcut:focus-search", onFocusSearch);
-  document.removeEventListener("keydown", onKeydown);
 });
 
 watch(
diff --git a/src/fabledassistant/models/__init__.py b/src/fabledassistant/models/__init__.py
index a503d65..78f0862 100644
--- a/src/fabledassistant/models/__init__.py
+++ b/src/fabledassistant/models/__init__.py
@@ -16,6 +16,9 @@ class Base(DeclarativeBase):
     pass
 
 
+from fabledassistant.models.base import CreatedAtMixin, TimestampMixin  # noqa: E402, F401
+
+
 from fabledassistant.models.note import Note, TaskPriority, TaskStatus  # noqa: E402, F401
 from fabledassistant.models.conversation import Conversation, Message  # noqa: E402, F401
 from fabledassistant.models.setting import Setting  # noqa: E402, F401
diff --git a/src/fabledassistant/models/base.py b/src/fabledassistant/models/base.py
new file mode 100644
index 0000000..76743bd
--- /dev/null
+++ b/src/fabledassistant/models/base.py
@@ -0,0 +1,21 @@
+from datetime import datetime, timezone
+
+from sqlalchemy import DateTime
+from sqlalchemy.orm import Mapped, mapped_column
+
+
+class TimestampMixin:
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )
+
+
+class CreatedAtMixin:
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
diff --git a/src/fabledassistant/models/conversation.py b/src/fabledassistant/models/conversation.py
index 9b6ac68..0834d05 100644
--- a/src/fabledassistant/models/conversation.py
+++ b/src/fabledassistant/models/conversation.py
@@ -1,14 +1,13 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import DateTime, ForeignKey, Index, Integer, Text
+from sqlalchemy import ForeignKey, Index, Integer, Text
 from sqlalchemy import inspect
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import CreatedAtMixin, TimestampMixin
 
 
-class Conversation(Base):
+class Conversation(Base, TimestampMixin):
     __tablename__ = "conversations"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -17,14 +16,6 @@ class Conversation(Base):
     )
     title: Mapped[str] = mapped_column(Text, default="")
     model: Mapped[str] = mapped_column(Text, default="")
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
-    )
 
     messages: Mapped[list["Message"]] = relationship(
         back_populates="conversation",
@@ -53,7 +44,7 @@ class Conversation(Base):
         }
 
 
-class Message(Base):
+class Message(Base, CreatedAtMixin):
     __tablename__ = "messages"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -67,9 +58,6 @@ class Message(Base):
         Integer, ForeignKey("notes.id", ondelete="SET NULL"), nullable=True
     )
     tool_calls: Mapped[list | None] = mapped_column(JSONB, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
 
     conversation: Mapped["Conversation"] = relationship(back_populates="messages")
 
diff --git a/src/fabledassistant/models/milestone.py b/src/fabledassistant/models/milestone.py
index 2d88c20..7312ce4 100644
--- a/src/fabledassistant/models/milestone.py
+++ b/src/fabledassistant/models/milestone.py
@@ -1,12 +1,11 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import DateTime, ForeignKey, Integer, Text
+from sqlalchemy import ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import TimestampMixin
 
 
-class Milestone(Base):
+class Milestone(Base, TimestampMixin):
     __tablename__ = "milestones"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -16,14 +15,6 @@ class Milestone(Base):
     description: Mapped[str | None] = mapped_column(Text, nullable=True)
     status: Mapped[str] = mapped_column(Text, default="active")
     order_index: Mapped[int] = mapped_column(Integer, default=0)
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
-    )
 
     def to_dict(self) -> dict:
         return {
diff --git a/src/fabledassistant/models/note.py b/src/fabledassistant/models/note.py
index db4868f..f317a27 100644
--- a/src/fabledassistant/models/note.py
+++ b/src/fabledassistant/models/note.py
@@ -1,11 +1,12 @@
 import enum
-from datetime import date, datetime, timezone
+from datetime import date
 
-from sqlalchemy import Date, DateTime, ForeignKey, Index, Integer, Text
+from sqlalchemy import Date, ForeignKey, Index, Integer, Text
 from sqlalchemy.dialects.postgresql import ARRAY
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import TimestampMixin
 
 
 class TaskStatus(str, enum.Enum):
@@ -21,7 +22,7 @@ class TaskPriority(str, enum.Enum):
     high = "high"
 
 
-class Note(Base):
+class Note(Base, TimestampMixin):
     __tablename__ = "notes"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -43,14 +44,6 @@ class Note(Base):
     status: Mapped[str | None] = mapped_column(Text, nullable=True)
     priority: Mapped[str | None] = mapped_column(Text, nullable=True)
     due_date: Mapped[date | None] = mapped_column(Date, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
-    )
 
     __table_args__ = (
         Index("ix_notes_tags", "tags", postgresql_using="gin"),
diff --git a/src/fabledassistant/models/note_draft.py b/src/fabledassistant/models/note_draft.py
index c6eed29..50be076 100644
--- a/src/fabledassistant/models/note_draft.py
+++ b/src/fabledassistant/models/note_draft.py
@@ -1,12 +1,11 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import DateTime, ForeignKey, Integer, Text
+from sqlalchemy import ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import TimestampMixin
 
 
-class NoteDraft(Base):
+class NoteDraft(Base, TimestampMixin):
     __tablename__ = "note_drafts"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -16,14 +15,6 @@ class NoteDraft(Base):
     original_body: Mapped[str] = mapped_column(Text)
     instruction: Mapped[str] = mapped_column(Text, default="")
     scope: Mapped[str] = mapped_column(Text, default="document")
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
-    )
 
     def to_dict(self) -> dict:
         return {
diff --git a/src/fabledassistant/models/note_version.py b/src/fabledassistant/models/note_version.py
index 688f998..93fc206 100644
--- a/src/fabledassistant/models/note_version.py
+++ b/src/fabledassistant/models/note_version.py
@@ -1,12 +1,11 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import ARRAY, DateTime, ForeignKey, Integer, Text
+from sqlalchemy import ARRAY, ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import CreatedAtMixin
 
 
-class NoteVersion(Base):
+class NoteVersion(Base, CreatedAtMixin):
     __tablename__ = "note_versions"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -15,9 +14,6 @@ class NoteVersion(Base):
     body: Mapped[str] = mapped_column(Text)
     title: Mapped[str] = mapped_column(Text, default="")
     tags: Mapped[list[str]] = mapped_column(ARRAY(Text), default=list)
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
 
     def to_dict(self, include_body: bool = True) -> dict:
         d: dict = {
diff --git a/src/fabledassistant/models/project.py b/src/fabledassistant/models/project.py
index 3268a3e..4f0de36 100644
--- a/src/fabledassistant/models/project.py
+++ b/src/fabledassistant/models/project.py
@@ -1,8 +1,8 @@
 import enum
-from datetime import datetime, timezone
-from sqlalchemy import DateTime, ForeignKey, Integer, Text
+from sqlalchemy import ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 from fabledassistant.models import Base
+from fabledassistant.models.base import TimestampMixin
 
 
 class ProjectStatus(str, enum.Enum):
@@ -11,7 +11,7 @@ class ProjectStatus(str, enum.Enum):
     archived = "archived"
 
 
-class Project(Base):
+class Project(Base, TimestampMixin):
     __tablename__ = "projects"
     id: Mapped[int] = mapped_column(primary_key=True)
     user_id: Mapped[int | None] = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=True)
@@ -20,8 +20,6 @@ class Project(Base):
     goal: Mapped[str] = mapped_column(Text, default="")
     status: Mapped[str] = mapped_column(Text, default="active")
     color: Mapped[str | None] = mapped_column(Text, nullable=True)  # hex color
-    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
-    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
 
     def to_dict(self) -> dict:
         return {
diff --git a/src/fabledassistant/models/push_subscription.py b/src/fabledassistant/models/push_subscription.py
index ff8263b..072afaf 100644
--- a/src/fabledassistant/models/push_subscription.py
+++ b/src/fabledassistant/models/push_subscription.py
@@ -1,10 +1,11 @@
-from datetime import datetime, timezone
+from datetime import datetime
 from sqlalchemy import DateTime, ForeignKey, Integer, Text, UniqueConstraint
 from sqlalchemy.orm import Mapped, mapped_column
 from fabledassistant.models import Base
+from fabledassistant.models.base import CreatedAtMixin
 
 
-class PushSubscription(Base):
+class PushSubscription(Base, CreatedAtMixin):
     __tablename__ = "push_subscriptions"
     id: Mapped[int] = mapped_column(primary_key=True)
     user_id: Mapped[int] = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"))
@@ -12,7 +13,6 @@ class PushSubscription(Base):
     p256dh: Mapped[str] = mapped_column(Text)
     auth: Mapped[str] = mapped_column(Text)
     user_agent: Mapped[str | None] = mapped_column(Text, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
     last_used: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
 
     __table_args__ = (
diff --git a/src/fabledassistant/models/task_log.py b/src/fabledassistant/models/task_log.py
index dc3ccb7..c6e7a9e 100644
--- a/src/fabledassistant/models/task_log.py
+++ b/src/fabledassistant/models/task_log.py
@@ -1,12 +1,11 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import DateTime, ForeignKey, Integer, Text
+from sqlalchemy import ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import TimestampMixin
 
 
-class TaskLog(Base):
+class TaskLog(Base, TimestampMixin):
     __tablename__ = "task_logs"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -14,14 +13,6 @@ class TaskLog(Base):
     user_id: Mapped[int] = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"))
     content: Mapped[str] = mapped_column(Text)
     duration_minutes: Mapped[int | None] = mapped_column(Integer, nullable=True)
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
-    )
 
     def to_dict(self) -> dict:
         return {
diff --git a/src/fabledassistant/models/user.py b/src/fabledassistant/models/user.py
index 703a52e..7fc7133 100644
--- a/src/fabledassistant/models/user.py
+++ b/src/fabledassistant/models/user.py
@@ -1,12 +1,11 @@
-from datetime import datetime, timezone
-
-from sqlalchemy import DateTime, Index, Text
+from sqlalchemy import Index, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
+from fabledassistant.models.base import CreatedAtMixin
 
 
-class User(Base):
+class User(Base, CreatedAtMixin):
     __tablename__ = "users"
 
     id: Mapped[int] = mapped_column(primary_key=True)
@@ -15,9 +14,6 @@ class User(Base):
     password_hash: Mapped[str | None] = mapped_column(Text, nullable=True)
     oauth_sub: Mapped[str | None] = mapped_column(Text, unique=True, nullable=True)
     role: Mapped[str] = mapped_column(Text, nullable=False, default="user")
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
-    )
 
     __table_args__ = (
         Index("ix_users_username", "username"),
diff --git a/src/fabledassistant/routes/chat.py b/src/fabledassistant/routes/chat.py
index a664322..352019d 100644
--- a/src/fabledassistant/routes/chat.py
+++ b/src/fabledassistant/routes/chat.py
@@ -6,6 +6,7 @@ import httpx
 from quart import Blueprint, Response, jsonify, request
 
 from fabledassistant.auth import login_required, get_current_user_id
+from fabledassistant.routes.utils import not_found
 from fabledassistant.config import Config
 from fabledassistant.services.chat import (
     add_message,
@@ -61,7 +62,7 @@ async def get_conversation_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
     result = conv.to_dict()
     note_ids = [m.context_note_id for m in conv.messages if m.context_note_id]
     note_map = await get_notes_by_ids(uid, note_ids) if note_ids else {}
@@ -80,7 +81,7 @@ async def delete_conversation_route(conv_id: int):
     uid = get_current_user_id()
     deleted = await delete_conversation(uid, conv_id)
     if not deleted:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
     return "", 204
 
 
@@ -95,7 +96,7 @@ async def update_conversation_route(conv_id: int):
         return jsonify({"error": "title or model is required"}), 400
     conv = await update_conversation(uid, conv_id, title=title, model=model)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
     return jsonify(conv.to_dict())
 
 
@@ -106,7 +107,7 @@ async def send_message_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
 
     data = await request.get_json()
     content = data.get("content", "").strip()
@@ -166,7 +167,7 @@ async def generation_stream_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
 
     buf = get_buffer(conv_id)
     if buf is None:
@@ -219,7 +220,7 @@ async def confirm_generation_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
 
     buf = get_buffer(conv_id)
     if buf is None or buf.state != GenerationState.RUNNING:
@@ -241,7 +242,7 @@ async def cancel_generation_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
 
     buf = get_buffer(conv_id)
     if buf is None or buf.state != GenerationState.RUNNING:
@@ -268,7 +269,7 @@ async def summarize_conversation_route(conv_id: int):
     uid = get_current_user_id()
     conv = await get_conversation(uid, conv_id)
     if conv is None:
-        return jsonify({"error": "Conversation not found"}), 404
+        return not_found("Conversation")
     model = await get_setting(uid, "default_model", Config.OLLAMA_MODEL) or Config.OLLAMA_MODEL
     try:
         note = await summarize_conversation_as_note(uid, conv_id, model)
diff --git a/src/fabledassistant/routes/milestones.py b/src/fabledassistant/routes/milestones.py
index 2e09832..d8471ce 100644
--- a/src/fabledassistant/routes/milestones.py
+++ b/src/fabledassistant/routes/milestones.py
@@ -4,6 +4,7 @@ import logging
 from quart import Blueprint, jsonify, request
 
 from fabledassistant.auth import login_required, get_current_user_id
+from fabledassistant.routes.utils import not_found
 from fabledassistant.services.milestones import (
     create_milestone,
     delete_milestone,
@@ -20,21 +21,22 @@ logger = logging.getLogger(__name__)
 milestones_bp = Blueprint("milestones", __name__, url_prefix="/api/projects")
 
 
+async def _milestone_dict(m) -> dict:
+    d = m.to_dict()
+    d.update(await get_milestone_progress(m.id))
+    return d
+
+
 @milestones_bp.route("/<int:project_id>/milestones", methods=["GET"])
 @login_required
 async def list_milestones_route(project_id: int):
     uid = get_current_user_id()
     project = await get_project(uid, project_id)
     if project is None:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
     status = request.args.get("status")
     milestones = await list_milestones(uid, project_id, status=status)
-    result = []
-    for m in milestones:
-        entry = m.to_dict()
-        progress = await get_milestone_progress(m.id)
-        entry.update(progress)
-        result.append(entry)
+    result = [await _milestone_dict(m) for m in milestones]
     return jsonify({"milestones": result})
 
 
@@ -44,7 +46,7 @@ async def create_milestone_route(project_id: int):
     uid = get_current_user_id()
     project = await get_project(uid, project_id)
     if project is None:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
     data = await request.get_json()
     if not data.get("title"):
         return jsonify({"error": "title is required"}), 400
@@ -55,9 +57,7 @@ async def create_milestone_route(project_id: int):
         description=data.get("description"),
         order_index=data.get("order_index", 0),
     )
-    entry = milestone.to_dict()
-    entry.update(await get_milestone_progress(milestone.id))
-    return jsonify(entry), 201
+    return jsonify(await _milestone_dict(milestone)), 201
 
 
 @milestones_bp.route("/<int:project_id>/milestones/<int:milestone_id>", methods=["GET"])
@@ -66,10 +66,8 @@ async def get_milestone_route(project_id: int, milestone_id: int):
     uid = get_current_user_id()
     milestone = await get_milestone(uid, milestone_id)
     if milestone is None or milestone.project_id != project_id:
-        return jsonify({"error": "Milestone not found"}), 404
-    entry = milestone.to_dict()
-    entry.update(await get_milestone_progress(milestone.id))
-    return jsonify(entry)
+        return not_found("Milestone")
+    return jsonify(await _milestone_dict(milestone))
 
 
 @milestones_bp.route("/<int:project_id>/milestones/<int:milestone_id>", methods=["PATCH"])
@@ -78,16 +76,14 @@ async def update_milestone_route(project_id: int, milestone_id: int):
     uid = get_current_user_id()
     milestone = await get_milestone(uid, milestone_id)
     if milestone is None or milestone.project_id != project_id:
-        return jsonify({"error": "Milestone not found"}), 404
+        return not_found("Milestone")
     data = await request.get_json()
     allowed = {"title", "description", "status", "order_index"}
     fields = {k: v for k, v in data.items() if k in allowed}
     updated = await update_milestone(uid, milestone_id, **fields)
     if updated is None:
-        return jsonify({"error": "Milestone not found"}), 404
-    entry = updated.to_dict()
-    entry.update(await get_milestone_progress(updated.id))
-    return jsonify(entry)
+        return not_found("Milestone")
+    return jsonify(await _milestone_dict(updated))
 
 
 @milestones_bp.route("/<int:project_id>/milestones/<int:milestone_id>", methods=["DELETE"])
@@ -96,10 +92,10 @@ async def delete_milestone_route(project_id: int, milestone_id: int):
     uid = get_current_user_id()
     milestone = await get_milestone(uid, milestone_id)
     if milestone is None or milestone.project_id != project_id:
-        return jsonify({"error": "Milestone not found"}), 404
+        return not_found("Milestone")
     deleted = await delete_milestone(uid, milestone_id)
     if not deleted:
-        return jsonify({"error": "Milestone not found"}), 404
+        return not_found("Milestone")
     return "", 204
 
 
@@ -109,7 +105,7 @@ async def get_milestone_tasks_route(project_id: int, milestone_id: int):
     uid = get_current_user_id()
     milestone = await get_milestone(uid, milestone_id)
     if milestone is None or milestone.project_id != project_id:
-        return jsonify({"error": "Milestone not found"}), 404
+        return not_found("Milestone")
     status_filter = request.args.get("status")
     limit = min(request.args.get("limit", 100, type=int), 500)
     offset = request.args.get("offset", 0, type=int)
diff --git a/src/fabledassistant/routes/notes.py b/src/fabledassistant/routes/notes.py
index 053c783..926da78 100644
--- a/src/fabledassistant/routes/notes.py
+++ b/src/fabledassistant/routes/notes.py
@@ -1,13 +1,13 @@
 import asyncio
 import logging
 import re
-from datetime import date
 
 from fabledassistant.services.embeddings import upsert_note_embedding
 
 from quart import Blueprint, Response, jsonify, request
 
 from fabledassistant.auth import login_required, get_current_user_id
+from fabledassistant.routes.utils import not_found, parse_iso_date
 from fabledassistant.config import Config
 from fabledassistant.services.assist import build_assist_messages
 from fabledassistant.services.generation_buffer import (
@@ -87,12 +87,9 @@ async def create_note_route():
     # Optional task fields
     status = data.get("status")
     priority = data.get("priority")
-    due_date = None
-    if data.get("due_date"):
-        try:
-            due_date = date.fromisoformat(data["due_date"])
-        except ValueError:
-            return jsonify({"error": "Invalid date format. Use YYYY-MM-DD."}), 400
+    due_date = parse_iso_date(data.get("due_date"), "due_date")
+    if isinstance(due_date, tuple):
+        return due_date
 
     note = await create_note(
         uid,
@@ -144,7 +141,7 @@ async def append_tag_route(note_id: int):
 
     note = await get_note(uid, note_id)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
 
     existing = list(note.tags or [])
     if tag not in existing:
@@ -162,7 +159,7 @@ async def get_note_by_title_route():
         return jsonify({"error": "title parameter is required"}), 400
     note = await get_note_by_title(uid, title)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     return jsonify(note.to_dict())
 
 
@@ -184,7 +181,7 @@ async def get_note_route(note_id: int):
     uid = get_current_user_id()
     note = await get_note(uid, note_id)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     return jsonify(note.to_dict())
 
 
@@ -200,10 +197,10 @@ async def update_note_route(note_id: int):
 
     if "due_date" in data:
         if data["due_date"]:
-            try:
-                fields["due_date"] = date.fromisoformat(data["due_date"])
-            except ValueError:
-                return jsonify({"error": "Invalid date format. Use YYYY-MM-DD."}), 400
+            result = parse_iso_date(data["due_date"], "due_date")
+            if isinstance(result, tuple):
+                return result
+            fields["due_date"] = result
         else:
             fields["due_date"] = None
 
@@ -211,7 +208,7 @@ async def update_note_route(note_id: int):
         fields["tags"] = data["tags"]
     note = await update_note(uid, note_id, **fields)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     text = f"{note.title}\n{note.body}".strip() if note.body else (note.title or "")
     if text:
         asyncio.create_task(upsert_note_embedding(note.id, uid, text))
@@ -228,15 +225,15 @@ async def patch_note_route(note_id: int):
         if key in data:
             fields[key] = data[key]
     if "due_date" in data:
-        try:
-            fields["due_date"] = date.fromisoformat(data["due_date"]) if data["due_date"] else None
-        except (ValueError, TypeError):
-            return jsonify({"error": "Invalid due_date format, expected YYYY-MM-DD"}), 400
+        result = parse_iso_date(data.get("due_date"), "due_date")
+        if isinstance(result, tuple):
+            return result
+        fields["due_date"] = result
     if "tags" in data:
         fields["tags"] = data["tags"]
     note = await update_note(uid, note_id, **fields)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     return jsonify(note.to_dict())
 
 
@@ -246,7 +243,7 @@ async def delete_note_route(note_id: int):
     uid = get_current_user_id()
     deleted = await delete_note(uid, note_id)
     if not deleted:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     return "", 204
 
 
@@ -474,7 +471,7 @@ async def upsert_draft_route(note_id: int):
     # Verify note ownership
     note = await get_note(uid, note_id)
     if note is None:
-        return jsonify({"error": "Note not found"}), 404
+        return not_found("Note")
     data = await request.get_json()
     draft = await upsert_draft(
         user_id=uid,
@@ -511,5 +508,5 @@ async def get_version_route(note_id: int, version_id: int):
     uid = get_current_user_id()
     version = await get_version(uid, note_id, version_id)
     if version is None:
-        return jsonify({"error": "Version not found"}), 404
+        return not_found("Version")
     return jsonify(version.to_dict(include_body=True))
diff --git a/src/fabledassistant/routes/projects.py b/src/fabledassistant/routes/projects.py
index b2ff08f..902e3b9 100644
--- a/src/fabledassistant/routes/projects.py
+++ b/src/fabledassistant/routes/projects.py
@@ -4,6 +4,7 @@ import logging
 from quart import Blueprint, jsonify, request
 
 from fabledassistant.auth import login_required, get_current_user_id
+from fabledassistant.routes.utils import not_found
 from fabledassistant.services.milestones import list_milestones
 from fabledassistant.services.notes import list_notes
 from fabledassistant.services.projects import (
@@ -52,7 +53,7 @@ async def get_project_route(project_id: int):
     uid = get_current_user_id()
     project = await get_project(uid, project_id)
     if project is None:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
     summary = await get_project_summary(uid, project_id)
     data = project.to_dict()
     data["summary"] = summary
@@ -68,7 +69,7 @@ async def update_project_route(project_id: int):
     fields = {k: v for k, v in data.items() if k in allowed}
     project = await update_project(uid, project_id, **fields)
     if project is None:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
     return jsonify(project.to_dict())
 
 
@@ -78,7 +79,7 @@ async def delete_project_route(project_id: int):
     uid = get_current_user_id()
     deleted = await delete_project(uid, project_id)
     if not deleted:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
     return "", 204
 
 
@@ -88,7 +89,7 @@ async def get_project_notes_route(project_id: int):
     uid = get_current_user_id()
     project = await get_project(uid, project_id)
     if project is None:
-        return jsonify({"error": "Project not found"}), 404
+        return not_found("Project")
 
     # type filter: "note", "task", or None (both)
     type_filter = request.args.get("type")
diff --git a/src/fabledassistant/routes/tasks.py b/src/fabledassistant/routes/tasks.py
index 2d058df..c6e4087 100644
--- a/src/fabledassistant/routes/tasks.py
+++ b/src/fabledassistant/routes/tasks.py
@@ -1,9 +1,8 @@
-from datetime import date
-
 from quart import Blueprint, jsonify, request
 
 from fabledassistant.auth import login_required, get_current_user_id
 from fabledassistant.models.note import TaskPriority, TaskStatus
+from fabledassistant.routes.utils import not_found, parse_iso_date
 from fabledassistant.services.notes import (
     create_note,
     delete_note,
@@ -28,13 +27,12 @@ async def list_tasks_route():
     limit = min(request.args.get("limit", 50, type=int), 500)
     offset = request.args.get("offset", 0, type=int)
 
-    due_before_str = request.args.get("due_before")
-    due_after_str = request.args.get("due_after")
-    try:
-        due_before = date.fromisoformat(due_before_str) if due_before_str else None
-        due_after = date.fromisoformat(due_after_str) if due_after_str else None
-    except ValueError:
-        return jsonify({"error": "Invalid date format. Use YYYY-MM-DD."}), 400
+    due_before = parse_iso_date(request.args.get("due_before"), "due_before")
+    if isinstance(due_before, tuple):
+        return due_before
+    due_after = parse_iso_date(request.args.get("due_after"), "due_after")
+    if isinstance(due_after, tuple):
+        return due_after
 
     tasks, total = await list_notes(
         uid,
@@ -61,12 +59,9 @@ async def create_task_route():
     body = data.get("body", "") or data.get("description", "")
     tags = data.get("tags", [])
 
-    due_date = None
-    if data.get("due_date"):
-        try:
-            due_date = date.fromisoformat(data["due_date"])
-        except ValueError:
-            return jsonify({"error": "Invalid date format. Use YYYY-MM-DD."}), 400
+    due_date = parse_iso_date(data.get("due_date"), "due_date")
+    if isinstance(due_date, tuple):
+        return due_date
 
     status = TaskStatus(data["status"]).value if "status" in data else TaskStatus.todo.value
     priority = (
@@ -94,7 +89,7 @@ async def get_task_route(task_id: int):
     uid = get_current_user_id()
     task = await get_note(uid, task_id)
     if task is None:
-        return jsonify({"error": "Task not found"}), 404
+        return not_found("Task")
     data = task.to_dict()
     if task.parent_id:
         parent = await get_note(uid, task.parent_id)
@@ -120,10 +115,10 @@ async def update_task_route(task_id: int):
 
     if "due_date" in data:
         if data["due_date"]:
-            try:
-                fields["due_date"] = date.fromisoformat(data["due_date"])
-            except ValueError:
-                return jsonify({"error": "Invalid date format. Use YYYY-MM-DD."}), 400
+            result = parse_iso_date(data["due_date"], "due_date")
+            if isinstance(result, tuple):
+                return result
+            fields["due_date"] = result
         else:
             fields["due_date"] = None
 
@@ -136,7 +131,7 @@ async def update_task_route(task_id: int):
 
     task = await update_note(uid, task_id, **fields)
     if task is None:
-        return jsonify({"error": "Task not found"}), 404
+        return not_found("Task")
     return jsonify(task.to_dict())
 
 
@@ -156,7 +151,7 @@ async def patch_task_status(task_id: int):
 
     task = await update_note(uid, task_id, status=status_val)
     if task is None:
-        return jsonify({"error": "Task not found"}), 404
+        return not_found("Task")
     return jsonify(task.to_dict())
 
 
@@ -166,5 +161,5 @@ async def delete_task_route(task_id: int):
     uid = get_current_user_id()
     deleted = await delete_note(uid, task_id)
     if not deleted:
-        return jsonify({"error": "Task not found"}), 404
+        return not_found("Task")
     return "", 204
diff --git a/src/fabledassistant/routes/utils.py b/src/fabledassistant/routes/utils.py
new file mode 100644
index 0000000..f3aa475
--- /dev/null
+++ b/src/fabledassistant/routes/utils.py
@@ -0,0 +1,17 @@
+from datetime import date
+
+from quart import jsonify
+
+
+def not_found(resource: str = "Item"):
+    return jsonify({"error": f"{resource} not found"}), 404
+
+
+def parse_iso_date(value: str | None, field: str = "date"):
+    """Parse an ISO date string. Returns a date, None, or a (response, 400) tuple."""
+    if not value:
+        return None
+    try:
+        return date.fromisoformat(value)
+    except ValueError:
+        return jsonify({"error": f"Invalid {field} format. Use YYYY-MM-DD."}), 400
diff --git a/summary.md b/summary.md
index bd880bc..d7ee859 100644
--- a/summary.md
+++ b/summary.md
@@ -12,6 +12,30 @@
 >    Include file-level details in the commit body when the change is non-trivial.
 
 ## Last Updated
+2026-03-06 — DRY refactoring pass: TimestampMixin, route helpers, shared composables, ConfirmDialog, shared CSS.
+
+**DRY refactoring pass (backend):**
+- `src/fabledassistant/models/base.py` (new): `TimestampMixin` (`created_at` + `updated_at`) and `CreatedAtMixin` (`created_at` only) — SQLAlchemy 2.0 `Mapped[]` mixins. Applied to all 10+ models (`Note`, `Project`, `Milestone`, `Conversation`, `Message`, `User`, `PushSubscription`, `TaskLog`, `NoteDraft`, `NoteVersion`), removing ~60 lines of duplicated column definitions.
+- `src/fabledassistant/routes/utils.py` (new): `not_found(resource)` → `(Response, 404)` and `parse_iso_date(value, field)` → `date | None | (Response, 400)`. Used across `notes.py`, `tasks.py`, `projects.py`, `milestones.py`, `chat.py`, replacing ~18 inline 404 blocks and ~4 duplicate date-parsing try/except blocks.
+- `routes/milestones.py`: `_milestone_dict(m)` local async helper replaces 5 repetitions of `entry = m.to_dict(); entry.update(await get_milestone_progress(m.id))`.
+
+**DRY refactoring pass (frontend):**
+- `frontend/src/composables/useAutoSave.ts` (new): `useAutoSave(dirty, saving, saveFn, intervalMs?)` — interval-based autosave with `onMounted`/`onUnmounted` lifecycle, guards on dirty+saving state.
+- `frontend/src/composables/useEditorGuards.ts` (new): `useEditorGuards(dirty, saveFn)` — registers Ctrl+S handler, `beforeunload` warning, and `onBeforeRouteLeave` confirm guard.
+- `frontend/src/composables/useTagSuggestions.ts` (new): `useTagSuggestions(title, body, tags, markDirty)` — encapsulates `/api/notes/suggest-tags` call and suggestion state.
+- `frontend/src/composables/useFloatingAssist.ts` (new): `useFloatingAssist(onRequest)` — floating selection-based assist button positioning.
+- `frontend/src/composables/useListKeyboardNavigation.ts` (new): `useListKeyboardNavigation<T>(items, navigateTo, rowSelector?, enabled?)` — j/k/Enter navigation with focus-in-input guard and optional `enabled` ref.
+- `frontend/src/components/ConfirmDialog.vue` (new): reusable confirm modal. Props: `title`, `message`, `confirmLabel` (default "Delete"), `danger` (default true). Emits `confirm`/`cancel`. Uses `<teleport to="body">` internally.
+- `frontend/src/assets/editor-shared.css`: added shared sidebar CSS (`.sidebar-toggle`, `.sidebar-content`, `.sb-field`, `.sb-label`, `.sb-select`, `.sb-input`, `.sb-divider` + mobile collapse rules) used by both editor views.
+- `frontend/src/assets/viewer-shared.css` (new): shared context-breadcrumb CSS (`.context-bar`, `.ctx-crumb*`) imported by `NoteViewerView` and `TaskViewerView`.
+- `NoteEditorView.vue`, `TaskEditorView.vue`: replaced ~120 lines each of duplicated floating-assist, tag-suggestion, autosave, and route-guard logic with composable calls; replaced inline `<teleport>` delete modal with `<ConfirmDialog>`; removed ~80 lines of duplicated scoped sidebar CSS.
+- `NotesListView.vue`, `TasksListView.vue`: replaced inline `activeIndex`/`onKeydown`/`scrollActiveIntoView` keyboard-nav (~25 lines each) with `useListKeyboardNavigation`. TasksListView passes `isFlat` computed ref as `enabled` guard.
+- `NoteViewerView.vue`, `TaskViewerView.vue`: removed ~40 lines of duplicate `.context-bar`/`.ctx-crumb*` scoped CSS; added `<style src="@/assets/viewer-shared.css" />`.
+- No behaviour changes. Net: −634 lines, +237 lines across 31 files.
+
+---
+
+## Previous Session
 2026-03-06 — Project-aware writing assist, link suggestions, project-scoped RAG, semantic note search tool, SSE done-event race fix, RAG snippet increase, sidebar include full body, Enter-to-submit assist.
 
 **SSE done-event race fix:** `routes/notes.py` and `routes/chat.py` — The SSE stream generator had a race condition where `yield buf.format_sse(event)` hands control back to the event loop, allowing the generation task to set `buf.state = COMPLETED` and append the `done` event between the last yield and the state check. The loop would then break without delivering the `done` event (containing `full_text`). Fixed by adding a final drain loop after the `while` exits in both stream generators. Added INFO-level logging to `run_assist_generation` showing `input_chars`, `output_chars`, event count, and done-event index.