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/tblossom_illustriousxl.json

@@ -1,7 +1,7 @@
 {
   "look_id": "tblossom_illustriousxl",
   "look_name": "Tblossom Illustriousxl",
-  "character_id": "",
+  "character_id": "blossom_ppg",
   "positive": "blossom_(ppg), 1girl, orange_hair, very_long_hair, high_ponytail, hair_bow, red_bow, huge_bow, pink_eyes, red_lips, pink_top, crop_top, midriff, navel, red_pants, belt, ribbon",
   "negative": "lowres, bad anatomy, bad hands, text, error, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality, normal quality, jpeg artifacts, signature, watermark, username, blurry, short_hair",
   "lora": {
@@ -21,4 +21,4 @@
     "crop_top",
     "red_pants"
   ]
-}
+}