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/checkpoints/illustrious_beretmixreal_v80.json

@@ -1,11 +1,11 @@
 {
-  "checkpoint_path": "Illustrious/beretMixReal_v80.safetensors",
+  "base_negative": "worst quality, low quality, normal quality, watermark, sexual fluids, loli",
+  "base_positive": "masterpiece, best quality, photo realistic, ultra detailed, realistic skin, ultra high res, 8k, very aesthetic, absurdres,",
+  "cfg": 7,
   "checkpoint_name": "beretMixReal_v80.safetensors",
-  "base_positive": "masterpiece, best quality, photo realistic, ultra detailed, realistic skin, ultra high res, 8k, very aesthetic, absurdres",
-  "base_negative": "worst quality, low quality, normal quality, watermark, sexual fluids",
-  "steps": 30,
-  "cfg": 7.0,
+  "checkpoint_path": "Illustrious/beretMixReal_v80.safetensors",
+  "sampler_name": "euler_ancestral",
   "scheduler": "normal",
-  "sampler_name":  "euler_ancestral",
+  "steps": 30,
   "vae": "integrated"
 }