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/presets/example_01.json

@@ -2,7 +2,7 @@
   "preset_id": "example_01",
   "preset_name": "Example Preset",
   "character": {
-    "character_id": "aerith_gainsborough",
+    "character_id": "anya_(spy_x_family)",
     "use_lora": true,
     "fields": {
       "identity": {
@@ -39,11 +39,11 @@
     }
   },
   "outfit": {
-    "outfit_id": null,
+    "outfit_id": "random",
     "use_lora": true
   },
   "action": {
-    "action_id": "random",
+    "action_id": null,
     "use_lora": true,
     "fields": {
       "full_body": true,
@@ -59,7 +59,7 @@
     "use_lora": true
   },
   "scene": {
-    "scene_id": "random",
+    "scene_id": null,
     "use_lora": true,
     "fields": {
       "background": true,
@@ -71,7 +71,7 @@
     }
   },
   "detailer": {
-    "detailer_id": null,
+    "detailer_id": "sts_age_slider_illustrious_v1",
     "use_lora": true
   },
   "look": {