Add extra prompts, endless generation, random character default, and small fixes

- Add extra positive/negative prompt textareas to all 9 detail pages with session persistence
- Add Endless generation button to all detail pages (continuous preview generation until stopped)
- Default character selector to "Random Character" on all secondary detail pages
- Fix queue clear endpoint (remove spurious auth check)
- Refactor app.py into routes/ and services/ modules
- Update CLAUDE.md with new architecture documentation
- Various data file updates and cleanup

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

data/clothing/extra_microskirt_xl_illustrious_v1_0.json

@@ -4,7 +4,7 @@
   "wardrobe": {
     "full_body": "",
     "headwear": "",
-    "top": "shirt",
+    "top": "",
     "bottom": "microskirt",
     "legwear": "",
     "footwear": "",
@@ -24,4 +24,4 @@
     "shirt",
     "suit"
   ]
-}
+}