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/aged_up_powerpuff_girls.json

@@ -1,14 +1,14 @@
 {
   "look_id": "aged_up_powerpuff_girls",
   "look_name": "Aged Up Powerpuff Girls",
-  "character_id": "",
+  "character_id": null,
   "positive": "powerpuff_girls, aged_up, tight_dress",
   "negative": "watermark, pubic_hair, same_face, bad_anatomy",
   "lora": {
     "lora_name": "Illustrious/Looks/Aged_up_Powerpuff_Girls.safetensors",
     "lora_weight": 1.0,
-    "lora_triggers": "blossom (powerpuff girls), bubbles (powerpuff girls), buttercup (powerpuff girls)",
-    "lora_weight_min": 1.0,
+    "lora_triggers": "ppg",
+    "lora_weight_min": 0.4,
     "lora_weight_max": 1.0
   },
   "tags": [