feat(modal-store): post-scoped cycle — open(id, { postImageIds }) pins prev/next to the array; canPrev/canNext + goPrev/goNext check the array index instead of current.value.neighbors when set. Gallery-context callers unchanged (default args clear scope)

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

frontend/src/stores/modal.js

@@ -6,14 +6,31 @@ export const useModalStore = defineStore('modal', () => {
   const api = useApi()
 
   const currentImageId = ref(null)
-  const current = ref(null)        // full image detail from API
+  const current = ref(null)
   const loading = ref(false)
   const error = ref(null)
 
-  async function open(id) {
+  // Post-scoped cycle. When set, prev/next cycles within this array
+  // (used by PostModal's PostImageGrid clicks). When null, prev/next
+  // falls back to current.value.neighbors (the gallery-store-driven
+  // /api/gallery/image/<id> neighbors).
+  const postImageIds = ref(null)
+  const postImageIndex = ref(0)
+
+  async function open (id, opts = {}) {
     currentImageId.value = id
     loading.value = true
     error.value = null
+    // Update post-scoped state if caller passed it; otherwise clear so
+    // the next open() from gallery context uses neighbors mode.
+    if (opts.postImageIds != null) {
+      postImageIds.value = opts.postImageIds
+      postImageIndex.value = opts.postImageIds.indexOf(id)
+      if (postImageIndex.value < 0) postImageIndex.value = 0
+    } else if (opts.clearPostScope !== false && postImageIds.value != null) {
+      postImageIds.value = null
+      postImageIndex.value = 0
+    }
     try {
       current.value = await api.get(`/api/gallery/image/${id}`)
     } catch (e) {
@@ -24,41 +41,58 @@ export const useModalStore = defineStore('modal', () => {
     }
   }
 
-  async function close() {
+  async function close () {
     currentImageId.value = null
     current.value = null
     error.value = null
+    postImageIds.value = null
+    postImageIndex.value = 0
   }
 
-  async function goPrev() {
-    if (current.value && current.value.neighbors.prev_id) {
+  async function goPrev () {
+    if (postImageIds.value != null) {
+      if (postImageIndex.value > 0) {
+        const newIdx = postImageIndex.value - 1
+        const newId = postImageIds.value[newIdx]
+        postImageIndex.value = newIdx
+        await open(newId, { postImageIds: postImageIds.value })
+      }
+      return
+    }
+    if (current.value && current.value.neighbors?.prev_id) {
       await open(current.value.neighbors.prev_id)
     }
   }
-  async function goNext() {
-    if (current.value && current.value.neighbors.next_id) {
+
+  async function goNext () {
+    if (postImageIds.value != null) {
+      if (postImageIndex.value < postImageIds.value.length - 1) {
+        const newIdx = postImageIndex.value + 1
+        const newId = postImageIds.value[newIdx]
+        postImageIndex.value = newIdx
+        await open(newId, { postImageIds: postImageIds.value })
+      }
+      return
+    }
+    if (current.value && current.value.neighbors?.next_id) {
       await open(current.value.neighbors.next_id)
     }
   }
 
-  async function reloadTags() {
+  async function reloadTags () {
     if (!currentImageId.value) return
     const tags = await api.get(`/api/images/${currentImageId.value}/tags`)
     if (current.value) current.value.tags = tags
   }
 
-  async function removeTag(tagId) {
+  async function removeTag (tagId) {
     if (!currentImageId.value) return
-    // Optimistic UI: remove locally first, restore on error.
     const prev = current.value.tags
     current.value.tags = current.value.tags.filter(t => t.id !== tagId)
     try {
-      // FC-2b: removal also records a per-image rejection (suggestions/dismiss
-      // is the rejection-recording endpoint) so the allowlist maintenance
-      // task won't re-apply this tag to this image.
       await api.delete(`/api/images/${currentImageId.value}/tags/${tagId}`)
       await api.post(`/api/images/${currentImageId.value}/suggestions/dismiss`, {
-        body: { tag_id: tagId }
+        body: { tag_id: tagId },
       })
     } catch (e) {
       current.value.tags = prev
@@ -67,25 +101,36 @@ export const useModalStore = defineStore('modal', () => {
     }
   }
 
-  async function addExistingTag(tagId) {
+  async function addExistingTag (tagId) {
     if (!currentImageId.value) return
     await api.post(`/api/images/${currentImageId.value}/tags`, {
-      body: { tag_id: tagId, source: 'manual' }
+      body: { tag_id: tagId, source: 'manual' },
     })
     await reloadTags()
   }
 
-  async function createAndAdd({ name, kind, fandom_id = null }) {
+  async function createAndAdd ({ name, kind, fandom_id = null }) {
     const tag = await api.post('/api/tags', { body: { name, kind, fandom_id } })
     await addExistingTag(tag.id)
   }
 
   const isOpen = computed(() => currentImageId.value !== null)
-  const canPrev = computed(() => current.value?.neighbors?.prev_id != null)
-  const canNext = computed(() => current.value?.neighbors?.next_id != null)
+  const canPrev = computed(() => {
+    if (postImageIds.value != null) return postImageIndex.value > 0
+    return current.value?.neighbors?.prev_id != null
+  })
+  const canNext = computed(() => {
+    if (postImageIds.value != null) {
+      return postImageIndex.value < (postImageIds.value.length - 1)
+    }
+    return current.value?.neighbors?.next_id != null
+  })
 
   return {
-    currentImageId, current, loading, error, isOpen, canPrev, canNext,
-    open, close, goPrev, goNext, reloadTags, removeTag, addExistingTag, createAndAdd
+    currentImageId, current, loading, error,
+    postImageIds, postImageIndex,
+    isOpen, canPrev, canNext,
+    open, close, goPrev, goNext,
+    reloadTags, removeTag, addExistingTag, createAndAdd,
   }
 })