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/xtrasmol_000019_1595565.json

@@ -1,19 +0,0 @@
-{
-  "look_id": "xtrasmol_000019_1595565",
-  "look_name": "Xtrasmol 000019 1595565",
-  "character_id": "",
-  "positive": "1girl, minigirl, size_difference, mature_female, solo",
-  "negative": "multiple_girls, simple_background, 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",
-  "lora": {
-    "lora_name": "Illustrious/Looks/XtraSmol-000019_1595565.safetensors",
-    "lora_weight": 0.6,
-    "lora_triggers": "teeny, tinygirl",
-    "lora_weight_min": 0.6,
-    "lora_weight_max": 0.6
-  },
-  "tags": [
-    "minigirl",
-    "size_difference",
-    "mature_female"
-  ]
-}