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/characters/android_21.json

@@ -0,0 +1,57 @@
+{
+  "character_id": "android_21",
+  "character_name": "Android 21",
+  "identity": {
+    "base_specs": "1girl, android_21, pale_skin",
+    "hair": "brown_hair, long_hair, big_hair, messy_hair",
+    "eyes": "blue_eyes, glasses",
+    "hands": "ring",
+    "arms": "",
+    "torso": "",
+    "pelvis": "",
+    "legs": "",
+    "feet": "",
+    "extra": ""
+  },
+  "defaults": {
+    "expression": "smile",
+    "pose": "standing",
+    "scene": "indoors, laboratory"
+  },
+  "wardrobe": {
+    "full_body": "",
+    "headwear": "",
+    "top": "lab_coat, red and blue checkered dress",
+    "bottom": "",
+    "legwear": "black_thighhighs",
+    "footwear": "high_heels",
+    "hands": "",
+    "accessories": "earrings, finger_ring"
+  },
+  "styles": {
+    "aesthetic": "anime",
+    "primary_color": "white",
+    "secondary_color": "blue",
+    "tertiary_color": "red"
+  },
+  "lora": {
+    "lora_name": "",
+    "lora_weight": 1.0,
+    "lora_weight_min": 0.7,
+    "lora_weight_max": 1.0,
+    "lora_triggers": ""
+  },
+  "tags": [
+    "android_21",
+    "1girl",
+    "long_hair",
+    "brown_hair",
+    "blue_eyes",
+    "glasses",
+    "lab_coat",
+    "checkered_dress",
+    "black_thighhighs",
+    "high_heels",
+    "dragon_ball"
+  ]
+}