fix(suggestions): resolve bare WD14 character names to existing "(Fandom)" tags

WD14 emits bare names (e.g. "Ruby Rose") while curated character/fandom
tags carry a fandom suffix ("Ruby Rose (RWBY)"). Two gaps caused a
duplicate, fandom-less tag to be created when users accepted a WD14
suggestion for an image that already had the curated version:

- Suggestion compute: bare character/copyright suggestions are now
  suppressed when the image already carries a `Name (Fandom)` variant,
  so the duplicate chip no longer surfaces.
- Accept endpoint: if the exact-name lookup misses for character/fandom
  kinds, we try a `Name (%)`-scoped lookup and attach the existing tag
  only when exactly one candidate matches. Zero or multiple matches
  fall through to prior behavior to avoid silently guessing across
  ambiguous fandoms.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/main.py

@@ -767,9 +767,27 @@ def accept_image_suggestion(image_id):
     tag = Tag.query.filter_by(name=tag_name).first()
     if tag is None:
         kind = _WD14_CATEGORY_TO_KIND.get(category)  # None for 'general'
-        tag = Tag(name=tag_name, kind=kind)
-        db.session.add(tag)
-        db.session.flush()
+        # WD14 emits bare names ("Ruby Rose") while curated character/fandom tags
+        # carry a fandom suffix ("Ruby Rose (RWBY)"). Try to auto-resolve a bare
+        # suggestion to an existing fandom-scoped tag — but only when exactly one
+        # candidate exists; zero/multiple falls through to creating a new tag so
+        # we don't silently guess across ambiguous matches (e.g. same name in
+        # multiple fandoms).
+        if kind in ('character', 'fandom'):
+            candidates = (
+                Tag.query
+                .filter(Tag.kind == kind)
+                .filter(Tag.name.ilike(f'{tag_name} (%)'))
+                .limit(2)
+                .all()
+            )
+            if len(candidates) == 1:
+                tag = candidates[0]
+                tag_name = tag.name  # feedback row logs the resolved name
+        if tag is None:
+            tag = Tag(name=tag_name, kind=kind)
+            db.session.add(tag)
+            db.session.flush()
 
     if tag not in image.tags:
         image.tags.append(tag)