feat(gallery): pinned filter bar (Phase 1)

Gallery now has in-view filtering, styled like the app's sticky v-tabs
chrome (pinned at top:64px under TopNav).

- GalleryFilterBar: combined tag+artist autocomplete (searches
  /api/tags + /api/artists), closable filter chips (multi-tag AND),
  media toggle (All/Images/Videos), Newest/Oldest sort, Clear. Writes all
  state to the URL via router.push.
- gallery store: filter is now { tag_ids, artist_id, media_type, sort,
  post_id }; applyFilterFromQuery makes the URL the single source of truth
  (deep-linkable, back-button works); chip labels resolved by id or
  pre-noted on pick. Replaces the standalone tag chip + setTag/PostFilter.
- GalleryView: renders the bar (hidden in post-detail), syncs route.query
  → store on mount + every query change.

Also untracks the transient .claude/scheduled_tasks.lock committed in
3f30327 and gitignores it.

Tests: store parses query → composable scroll params, post_id exclusivity,
newest-sort omitted, label pre-seed, single initial fetch.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/views/GalleryView.vue

@@ -12,13 +12,7 @@
     <div class="fc-gallery-layout">
       <div class="fc-gallery-layout__main">
         <PostInfoHeader />
-        <div v-if="store.filter.tag_id != null" class="fc-gallery-activefilter">
-          <v-chip
-            color="accent" variant="tonal" closable
-            prepend-icon="mdi-tag"
-            @click:close="clearTagFilter"
-          >Tag: {{ store.filterTagName || `#${store.filter.tag_id}` }}</v-chip>
-        </div>
+        <GalleryFilterBar v-if="store.filter.post_id == null" />
         <EmptyState v-if="store.isEmpty" />
         <GalleryGrid v-else @open="openImage" />
       </div>
@@ -31,10 +25,11 @@
 
 <script setup>
 import { onMounted, watch } from 'vue'
-import { useRoute, useRouter } from 'vue-router'
+import { useRoute } from 'vue-router'
 import { useGalleryStore } from '../stores/gallery.js'
 import { useModalStore } from '../stores/modal.js'
 import GalleryGrid from '../components/gallery/GalleryGrid.vue'
+import GalleryFilterBar from '../components/gallery/GalleryFilterBar.vue'
 import TimelineSidebar from '../components/gallery/TimelineSidebar.vue'
 import EmptyState from '../components/gallery/EmptyState.vue'
 import PostInfoHeader from '../components/gallery/PostInfoHeader.vue'
@@ -45,40 +40,19 @@ const store = useGalleryStore()
 const modal = useModalStore()
 const sel = useGallerySelectionStore()
 const route = useRoute()
-const router = useRouter()
 
-onMounted(async () => {
-  const postId = parseInt(route.query.post_id, 10)
-  const tagId = parseInt(route.query.tag_id, 10)
-  if (!isNaN(postId)) store.setPostFilter(postId)
-  else if (!isNaN(tagId)) store.setTagFilter(tagId)
-  await store.loadInitial()
-  await store.loadTimeline()
-})
+// The URL query is the single source of truth for filters. Apply it on
+// mount and on any query change (filter bar pushes, back button, deep-link).
+onMounted(() => store.applyFilterFromQuery(route.query))
 
-watch(() => route.query.tag_id, (q) => {
+watch(() => route.query, (q) => {
   sel.clear()  // result set changed — selected ids are no longer valid
-  const tagId = parseInt(q, 10)
-  store.setTagFilter(isNaN(tagId) ? null : tagId)
-})
-
-watch(() => route.query.post_id, (q) => {
-  sel.clear()  // result set changed — selected ids are no longer valid
-  const postId = parseInt(q, 10)
-  store.setPostFilter(isNaN(postId) ? null : postId)
+  store.applyFilterFromQuery(q)
 })
 
 function openImage(id) {
   modal.open(id)
 }
-
-// Clear the active tag filter by dropping it from the URL; the route
-// watcher above resets the store filter and reloads.
-function clearTagFilter() {
-  const q = { ...route.query }
-  delete q.tag_id
-  router.push({ query: q })
-}
 </script>
 
 <style scoped>
@@ -88,7 +62,6 @@ function clearTagFilter() {
   align-items: flex-start;
 }
 .fc-gallery-layout__main { flex: 1; min-width: 0; }
-.fc-gallery-activefilter { margin-bottom: 12px; }
 .fc-gallery-layout__sidebar { flex-shrink: 0; }
 
 @media (max-width: 900px) {