feat(suggestions): tag-input dropdown searches the full prediction set

The typed dropdown sourced the threshold-filtered panel list (>= 0.70 general),
so low-confidence actions/features the model DID predict never appeared — forcing
hand-typed custom tags instead of accepting the model's canonical formatting.

Add a threshold override: SuggestionService.for_image(threshold_override=) and
GET /images/<id>/suggestions?min=<f> surface EVERY stored prediction (down to the
0.05 store floor), alias-resolved and normalized, still excluding applied/rejected
and unsurfaced categories. The suggestions store gains allByCategory + loadAll
(min=0); the dropdown searches that full set (cap 20), while the Suggestions panel
stays curated at the configured threshold. Accept/dismiss drop from both lists.

Operator-asked 2026-06-09. Test: a 0.30 general prediction is hidden by default
but surfaced with threshold_override=0.0; unsurfaced categories still excluded.

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

frontend/src/stores/suggestions.js

@@ -16,9 +16,14 @@ export const CATEGORY_LABELS = {
 
 export const useSuggestionsStore = defineStore('suggestions', () => {
   const api = useApi()
-  const byCategory = ref({})       // { category: [suggestion, ...] }
+  const byCategory = ref({})       // { category: [suggestion, ...] } — panel (≥ threshold)
+  // The typed tag-input dropdown searches the model's FULL prediction set for
+  // the image (min=0, down to the store floor) so low-confidence actions/
+  // features can be picked in canonical formatting (operator-asked 2026-06-09).
+  const allByCategory = ref({})
   const { loading, error, run } = useAsyncAction({ errorAs: 'message' })
   let currentImageId = null
+  const inflightAll = useInflightToken()
   // Audit 2026-06-02: this store had no inflight guard — a late
   // /suggestions response from a prior image could overwrite
   // byCategory while currentImageId pointed at a new one, and
@@ -42,10 +47,41 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
     })
   }
 
-  function _drop(category, predicate) {
-    const list = byCategory.value[category]
-    if (!list) return
-    byCategory.value[category] = list.filter(s => !predicate(s))
+  // Load the full prediction set for the dropdown (separate inflight guard so a
+  // late response from a prior image can't overwrite the current one's list).
+  async function loadAll(imageId) {
+    inflightAll.cancel()
+    allByCategory.value = {}
+    const t = inflightAll.claim()
+    try {
+      const body = await api.get(`/api/images/${imageId}/suggestions`, {
+        params: { min: 0 },
+      })
+      if (!t.isCurrent()) return
+      allByCategory.value = body.by_category || {}
+    } catch {
+      // Dropdown is best-effort — the panel surfaces load errors.
+    }
+  }
+
+  // A stable identity for a suggestion across the two lists (panel vs dropdown
+  // are separate fetches, so object identity differs): tag id when known, else
+  // the raw display key.
+  function _keyOf(s) {
+    return s.canonical_tag_id != null
+      ? `id:${s.canonical_tag_id}`
+      : `raw:${s.category}:${(s.display_name || '').toLowerCase()}`
+  }
+
+  // Drop an accepted/dismissed suggestion from BOTH the panel list and the
+  // dropdown's full list so it can't reappear in either surface.
+  function _dropEverywhere(suggestion) {
+    const key = _keyOf(suggestion)
+    const cat = suggestion.category
+    for (const map of [byCategory.value, allByCategory.value]) {
+      const list = map[cat]
+      if (list) map[cat] = list.filter(s => _keyOf(s) !== key)
+    }
   }
 
   async function accept(suggestion) {
@@ -70,7 +106,7 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
     // Only drop from THIS image's category list — if the user navigated,
     // the new image has its own suggestions and this drop would corrupt them.
     if (currentImageId === imageId) {
-      _drop(suggestion.category, s => s === suggestion)
+      _dropEverywhere(suggestion)
     }
     toast({
       text: `Tagged: ${suggestion.display_name}`,
@@ -89,7 +125,7 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
       }
     })
     if (currentImageId === imageId) {
-      _drop(suggestion.category, s => s === suggestion)
+      _dropEverywhere(suggestion)
     }
     toast({
       text: `Aliased & tagged: ${suggestion.display_name}`,
@@ -109,12 +145,12 @@ export const useSuggestionsStore = defineStore('suggestions', () => {
       })
     }
     if (currentImageId === imageId) {
-      _drop(suggestion.category, s => s === suggestion)
+      _dropEverywhere(suggestion)
     }
   }
 
   return {
-    byCategory, loading, error,
-    load, accept, aliasAccept, dismiss
+    byCategory, allByCategory, loading, error,
+    load, loadAll, accept, aliasAccept, dismiss
   }
 })