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/looks/becky_illustrious.json

@@ -1,7 +1,7 @@
 {
   "look_id": "becky_illustrious",
   "look_name": "Becky Illustrious",
-  "character_id": "",
+  "character_id": "becky_blackbell",
   "positive": "becky_blackbell, spy_x_family, 1girl, solo, brown_eyes, brown_hair, short_hair, twintails, flat_chest, hairclip, hair_scrunchie, white_scrunchie, eden_academy_school_uniform, neck_ribbon, red_ribbon, collared_shirt, black_dress, gold_trim, black_sleeves, long_sleeves",
   "negative": "long_hair, mature_female",
   "lora": {
@@ -19,4 +19,4 @@
     "brown_hair",
     "brown_eyes"
   ]
-}
+}