Code review fixes: wardrobe migration, response validation, path traversal guard, deduplication

- Migrate 11 character JSONs from old wardrobe keys to _BODY_GROUP_KEYS format
- Add is_favourite/is_nsfw columns to Preset model
- Add HTTP response validation and timeouts to ComfyUI client
- Add path traversal protection on replace cover route
- Deduplicate services/mcp.py (4 functions → 2 generic + 2 wrappers)
- Extract apply_library_filters() and clean_html_text() shared helpers
- Add named constants for 17 ComfyUI workflow node IDs
- Fix bare except clauses in services/llm.py
- Fix tags schema in ensure_default_outfit() (list → dict)
- Convert f-string logging to lazy % formatting
- Add 5-minute polling timeout to frontend waitForJob()
- Improve migration error handling (non-duplicate errors log at WARNING)
- Update CLAUDE.md to reflect all changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

data/characters/shiki_senran_kagura.json

@@ -16,14 +16,13 @@
     "scene": ""
   },
   "wardrobe": {
-    "full_body": "black_dress, frilled_dress, gothic_lolita",
-    "headwear": "black_hat, mini_hat",
-    "top": "",
-    "bottom": "",
-    "legwear": "thighhighs, black_thighhighs",
-    "footwear": "black_footwear",
-    "hands": "",
-    "accessories": "cross_necklace, scythe"
+    "base": "black_dress, frilled_dress, gothic_lolita",
+    "head": "black_hat, mini_hat",
+    "upper_body": "",
+    "lower_body": "",
+    "additional": "cross_necklace, scythe",
+    "feet": "thighhighs, black_thighhighs, black_footwear",
+    "hands": ""
   },
   "styles": {
     "aesthetic": "gothic_lolita",