feat(bulk): IR-style BulkEditorPanel + GalleryView select toggle and wiring

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/views/GalleryView.vue

@@ -1,5 +1,13 @@
 <template>
   <v-container fluid class="py-6">
+    <v-btn
+      class="fc-select-toggle"
+      :color="sel.isSelectMode ? 'accent' : undefined"
+      :variant="sel.isSelectMode ? 'flat' : 'tonal'"
+      size="small"
+      @click="sel.isSelectMode ? sel.exitSelectMode() : sel.enterSelectMode()"
+    >{{ sel.isSelectMode ? 'Done' : 'Select' }}</v-btn>
+
     <div class="fc-gallery-layout">
       <div class="fc-gallery-layout__main">
         <EmptyState v-if="store.isEmpty" />
@@ -12,6 +20,7 @@
       v-if="modal.currentImageId !== null"
       @close="closeImage"
     />
+    <BulkEditorPanel />
   </v-container>
 </template>
 
@@ -24,9 +33,12 @@ import GalleryGrid from '../components/gallery/GalleryGrid.vue'
 import TimelineSidebar from '../components/gallery/TimelineSidebar.vue'
 import EmptyState from '../components/gallery/EmptyState.vue'
 import ImageViewer from '../components/modal/ImageViewer.vue'
+import BulkEditorPanel from '../components/gallery/BulkEditorPanel.vue'
+import { useGallerySelectionStore } from '../stores/gallerySelection.js'
 
 const store = useGalleryStore()
 const modal = useModalStore()
+const sel = useGallerySelectionStore()
 const router = useRouter()
 const route = useRoute()
 
@@ -41,6 +53,7 @@ onMounted(async () => {
 })
 
 watch(() => route.query.tag_id, (q) => {
+  sel.clear()  // result set changed — selected ids are no longer valid
   const tagId = parseInt(q, 10)
   store.setTagFilter(isNaN(tagId) ? null : tagId)
 })
@@ -69,6 +82,9 @@ function closeImage() {
 }
 .fc-gallery-layout__main { flex: 1; min-width: 0; }
 .fc-gallery-layout__sidebar { flex-shrink: 0; }
+.fc-select-toggle {
+  position: absolute; top: 12px; right: 16px; z-index: 1101;
+}
 
 @media (max-width: 900px) {
   .fc-gallery-layout { flex-direction: column-reverse; }