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/princess_bubblegum.json

@@ -0,0 +1,66 @@
+{
+  "character_id": "princess_bubblegum",
+  "character_name": "Princess Bubblegum",
+  "identity": {
+    "base_specs": "1girl, princess_bonnibel_bubblegum, pink_skin,",
+    "hair": "pink_hair, long_hair, gum_hair",
+    "eyes": "black_eyes, dot_eyes, simple eyes",
+    "hands": "pink nails",
+    "arms": "",
+    "torso": "",
+    "pelvis": "",
+    "legs": "",
+    "feet": "",
+    "extra": ""
+  },
+  "defaults": {
+    "expression": "smile",
+    "pose": "standing",
+    "scene": "candy_kingdom"
+  },
+  "wardrobe": {
+    "default": {
+      "full_body": "pink_dress, ",
+      "headwear": "crown, gold_crown, blue_gemstone_on_crown, purple_collar, ",
+      "top": "puffy_sleeves",
+      "bottom": "purple belt",
+      "legwear": "",
+      "footwear": "",
+      "hands": "",
+      "accessories": "tiara"
+    },
+    "scientist": {
+      "full_body": "",
+      "headwear": "crown, gold_crown, blue_gemstone_on_crown, tied hair, safety goggles",
+      "top": "white lab coat",
+      "bottom": "",
+      "legwear": "",
+      "footwear": "",
+      "hands": "purple cuffs",
+      "accessories": "tiara"
+    }
+  },
+  "styles": {
+    "aesthetic": "adventure_time style,",
+    "primary_color": "pink",
+    "secondary_color": "purple",
+    "tertiary_color": "gold"
+  },
+  "lora": {
+    "lora_name": "Illustrious/Looks/Bubblegum_ILL.safetensors",
+    "lora_weight": 1.0,
+    "lora_weight_min": 0.7,
+    "lora_weight_max": 1.0,
+    "lora_triggers": ""
+  },
+  "tags": [
+    "princess_bonnibel_bubblegum",
+    "adventure_time",
+    "pink_hair",
+    "pink_skin",
+    "pink_dress",
+    "crown",
+    "long_hair",
+    "cartoon_style"
+  ]
+}