feat(gallery): OR/exclude tag filtering — light chips + advanced builder (#6b/c/d)

Cluster A, milestone #97. Completes the frontend of the structured tag filter
(backend landed in 23fab98).

#6b store: gallery.filter gains tag_or (OR-groups) + tag_exclude; one model,
serialized via tag_or (repeated key) + tag_not across activeFilterParam/
filterToQuery/applyFilterFromQuery/cloneFilter/loadSimilar; _resolveLabels
resolves names for every referenced id. useApi now appends array param values
as a repeated key (tag_or=a&tag_or=b).

#6c light editor (GalleryFilterBar): autocomplete pick → include chip; click a
chip body to flip include↔exclude (exclude = red minus); ✕ removes. An
"N OR-groups" chip + an Advanced button open the builder.

#6d advanced editor (TagQueryBuilder.vue + common/TagPicker.vue): AND-of-OR
group builder + NOT list. Unifies includes+OR-groups into one groups view,
splits back to tag_ids/tag_or on Apply so the URL stays compact. Writes the
same model the light chips edit.

Store serialization round-trip tests added.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XCUHUGQLrBrkgyk1t49kpX

frontend/src/stores/gallery.js

@@ -24,6 +24,10 @@ export const useGalleryStore = defineStore('gallery', () => {
   const filter = ref({
     tag_ids: [], artist_id: null, media_type: null,
     sort: 'newest', post_id: null,
+    // #6 structured tag filter (AND-of-OR + exclude). tag_ids are the AND
+    // "include" singletons (light editor + back-compat); tag_or is a list of
+    // OR-groups (each group ORs, groups AND); tag_exclude is the NOT set.
+    tag_or: [], tag_exclude: [],
     // Phase-2 faceted refine params.
     platform: null, untagged: false, no_artist: false,
     date_from: null, date_to: null,
@@ -102,6 +106,9 @@ export const useGalleryStore = defineStore('gallery', () => {
       const f = filter.value
       const params = { similar_to: f.similar_to, limit: 100 }
       if (f.tag_ids.length) params.tag_id = f.tag_ids.join(',')
+      const orParam = _orGroupsParam(f.tag_or)
+      if (orParam.length) params.tag_or = orParam
+      if (f.tag_exclude.length) params.tag_not = f.tag_exclude.join(',')
       if (f.artist_id) params.artist_id = f.artist_id
       if (f.media_type) params.media = f.media_type
       if (f.platform) params.platform = f.platform
@@ -142,6 +149,9 @@ export const useGalleryStore = defineStore('gallery', () => {
     if (filter.value.post_id) return { post_id: filter.value.post_id }
     const p = {}
     if (filter.value.tag_ids.length) p.tag_id = filter.value.tag_ids.join(',')
+    const orParam = _orGroupsParam(filter.value.tag_or)
+    if (orParam.length) p.tag_or = orParam  // array → repeated tag_or= key
+    if (filter.value.tag_exclude.length) p.tag_not = filter.value.tag_exclude.join(',')
     if (filter.value.artist_id) p.artist_id = filter.value.artist_id
     if (filter.value.media_type) p.media = filter.value.media_type
     if (filter.value.sort && filter.value.sort !== 'newest') p.sort = filter.value.sort
@@ -177,6 +187,8 @@ export const useGalleryStore = defineStore('gallery', () => {
   async function applyFilterFromQuery(q) {
     filter.value = {
       tag_ids: _parseIds(q.tag_id),
+      tag_or: _parseGroups(q.tag_or),
+      tag_exclude: _parseIds(q.tag_not),
       artist_id: _toId(q.artist_id),
       media_type: ['image', 'video'].includes(q.media) ? q.media : null,
       sort: q.sort === 'oldest' ? 'oldest' : 'newest',
@@ -211,6 +223,14 @@ export const useGalleryStore = defineStore('gallery', () => {
     if (!raw) return []
     return String(raw).split(',').map(Number).filter((n) => Number.isInteger(n) && n > 0)
   }
+  // tag_or arrives from the URL as a string (one group) or string[] (many);
+  // each value is a comma-separated OR-group. Normalize to ids-of-ids, dropping
+  // empties so a stray `tag_or=` can't become a match-nothing group.
+  function _parseGroups(raw) {
+    if (raw == null) return []
+    const values = Array.isArray(raw) ? raw : [raw]
+    return values.map(_parseIds).filter((g) => g.length)
+  }
 
   // Pre-seed a label so a freshly-picked chip shows its name without a
   // round-trip; the bar calls these before pushing the new URL.
@@ -218,7 +238,14 @@ export const useGalleryStore = defineStore('gallery', () => {
   function noteArtistLabel(name) { artistLabel.value = name || null }
 
   async function _resolveLabels() {
-    for (const id of filter.value.tag_ids) {
+    // Every tag id referenced anywhere in the structured filter needs a chip
+    // label — includes, every OR-group member, and excludes.
+    const allTagIds = new Set([
+      ...filter.value.tag_ids,
+      ...filter.value.tag_or.flat(),
+      ...filter.value.tag_exclude,
+    ])
+    for (const id of allTagIds) {
       if (tagLabels.value[id]) continue
       try {
         const t = await api.get(`/api/tags/${id}`)
@@ -252,7 +279,10 @@ export const useGalleryStore = defineStore('gallery', () => {
 // the exclusive post-detail view.
 export function cloneFilter(f) {
   return {
-    tag_ids: [...f.tag_ids], artist_id: f.artist_id, media_type: f.media_type,
+    tag_ids: [...f.tag_ids],
+    tag_or: (f.tag_or || []).map((g) => [...g]),  // deep-clone the groups
+    tag_exclude: [...(f.tag_exclude || [])],
+    artist_id: f.artist_id, media_type: f.media_type,
     sort: f.sort, platform: f.platform, untagged: f.untagged,
     no_artist: f.no_artist, date_from: f.date_from, date_to: f.date_to,
     similar_to: f.similar_to,
@@ -262,6 +292,9 @@ export function cloneFilter(f) {
 export function filterToQuery(f) {
   const q = {}
   if (f.tag_ids?.length) q.tag_id = f.tag_ids.join(',')
+  const orParam = _orGroupsParam(f.tag_or)
+  if (orParam.length) q.tag_or = orParam  // array → repeated query key
+  if (f.tag_exclude?.length) q.tag_not = f.tag_exclude.join(',')
   if (f.artist_id) q.artist_id = String(f.artist_id)
   if (f.media_type) q.media = f.media_type
   if (f.sort && f.sort !== 'newest') q.sort = f.sort
@@ -274,6 +307,15 @@ export function filterToQuery(f) {
   return q
 }
 
+// Serialize OR-groups to repeated-param form: [[1,2],[3]] → ['1,2','3'],
+// dropping empty groups. Shared by the store's activeFilterParam and the
+// router-facing filterToQuery so both write tag_or the same way.
+function _orGroupsParam(groups) {
+  return (groups || [])
+    .map((g) => (g || []).join(','))
+    .filter((s) => s.length)
+}
+
 function mergeGroups(existing, incoming) {
   // Merge sequential groups with the same (year, month) instead of duplicating.
   const merged = [...existing]