fix(tag-prefix): drop artist/meta/rating from KNOWN_KINDS — artist tags retired in FC-2d-vii-c (provenance is its own axis), meta/rating retired by operator 2026-05-26. User-typeable prefixes now just character/fandom/series. Frontend placeholder + icon map + client-side mirror updated; new test confirms retired prefixes parse as literal text.

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

frontend/src/components/modal/TagAutocomplete.vue

@@ -2,7 +2,7 @@
   <div class="fc-tag-autocomplete">
     <v-text-field
       v-model="query"
-      placeholder="Add tag (or kind:name — artist/character/fandom/series/meta/rating)"
+      placeholder="Add tag (or kind:name — character/fandom/series)"
       density="compact" hide-details
       @keydown.down.prevent="moveHighlight(1)"
       @keydown.up.prevent="moveHighlight(-1)"
@@ -71,12 +71,11 @@ const fandomDialog = ref(false)
 let pendingNewName = null
 
 const KNOWN_KINDS = new Set([
-  'artist', 'character', 'fandom', 'series', 'meta', 'rating',
+  'character', 'fandom', 'series',
 ])
 const KIND_ICONS = {
-  general: 'mdi-tag', artist: 'mdi-palette', character: 'mdi-account-circle',
+  general: 'mdi-tag', character: 'mdi-account-circle',
   fandom: 'mdi-book-open-page-variant', series: 'mdi-bookshelf',
-  meta: 'mdi-cog-outline', rating: 'mdi-shield-check-outline',
 }
 function iconFor (k) { return KIND_ICONS[k] || 'mdi-tag' }