fix(suggestions): rejected tags stay rejected per image

Adds a per-image rejection filter to get_suggestions so once the user
clicks ✕ on an auto-accepted chip (or rejects a regular suggestion
via the existing ✕ button), that tag name stops reappearing in
suggestions — including auto_accept candidates.

Without this filter, the undo flow was cosmetic: the user's ✕
removed the tag from this image and logged a SuggestionFeedback
decision='rejected' row, but the next modal load re-ran auto-accept
against the same unchanged WD14 predictions and re-attached the same
tag. Rinse, repeat.

Implementation: _rejected_names_for_image(image_id) reads distinct
tag_names from suggestion_feedback where decision='rejected' for
this image. get_suggestions filters merged results against that set
alongside the existing blocklist filter. Both auto-accept candidates
and the three core categories respect the filter.

Tested on image 222 at threshold=0.9: first load auto-applied 23
general tags; rejected '1girl'; second load auto_accepted.count=0,
general suggestions had 10 new items, '1girl' absent from both.

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

app/services/tag_suggestions.py

@@ -114,6 +114,27 @@ def _blocklisted_names() -> set[str]:
     return {row[0] for row in db.session.query(TagSuggestionBlocklistEntry.name).all()}
 
 
+def _rejected_names_for_image(image_id: int) -> set[str]:
+    """Tag names the user has rejected for this specific image. Includes
+    both explicit ✕ rejections on raw suggestions and the ✕/⊘ undo actions
+    on auto-accepted tags (both go through /suggestions/reject which writes
+    decision='rejected' rows). Once rejected for an image, a name stays
+    suppressed for that image so auto-accept doesn't re-apply it on the
+    next modal open."""
+    from app.models import SuggestionFeedback
+    rows = (
+        db.session
+        .query(SuggestionFeedback.tag_name)
+        .filter(
+            SuggestionFeedback.image_id == image_id,
+            SuggestionFeedback.decision == 'rejected',
+        )
+        .distinct()
+        .all()
+    )
+    return {r[0] for r in rows}
+
+
 
 
 def _wd14_suggestions(image_id: int, cfg: dict, already: set[str]) -> list[dict]:
@@ -247,6 +268,14 @@ def get_suggestions(
     if blocklist:
         merged = [s for s in merged if s['name'] not in blocklist]
 
+    # Drop names the user has already rejected for THIS image. Without this,
+    # auto-accept re-applies the same WD14 prediction every time the modal
+    # loads, and the user's ✕ click on an auto-accepted chip is immediately
+    # undone on the next view.
+    per_image_rejected = _rejected_names_for_image(image_id)
+    if per_image_rejected:
+        merged = [s for s in merged if s['name'] not in per_image_rejected]
+
     if existing_all is None:
         existing_all = _existing_tag_names()