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/2b.json

@@ -0,0 +1,58 @@
+{
+  "character_id": "2b",
+  "character_name": "2B",
+  "identity": {
+    "base_specs": "1girl, 2b_(nier:automata),  pale_skin",
+    "hair": "short_hair, white_hair, bob_cut, bangs",
+    "eyes": "blue_eyes",
+    "hands": "white nails",
+    "arms": "",
+    "torso": "small breasts",
+    "pelvis": "",
+    "legs": "",
+    "feet": "",
+    "extra": ""
+  },
+  "defaults": {
+    "expression": "",
+    "pose": "",
+    "scene": ""
+  },
+  "wardrobe": {
+    "full_body": "black_dress, lace-trimmed_dress, gothic_lolita",
+    "headwear": " blindfold,",
+    "top": "black_dress, cleavage_cutout, feather_trim",
+    "bottom": "short_dress,",
+    "legwear": "thighhighs",
+    "footwear": "thigh_boots, black_boots, high_heels",
+    "hands": "black_gloves, ",
+    "accessories": "katana, sword_on_back"
+  },
+  "styles": {
+    "aesthetic": "gothic_lolita, science_fiction, dark_atmosphere",
+    "primary_color": "black",
+    "secondary_color": "white",
+    "tertiary_color": "silver"
+  },
+  "lora": {
+    "lora_name": "",
+    "lora_weight": 1.0,
+    "lora_weight_min": 0.7,
+    "lora_weight_max": 1.0,
+    "lora_triggers": "2b_(nier:automata)"
+  },
+  "tags": [
+    "1girl",
+    "2b_(nier:automata)",
+    "short_hair",
+    "white_hair",
+    "bob_cut",
+    "blindfold",
+    "black_dress",
+    "gothic_lolita",
+    "thigh_boots",
+    "black_gloves",
+    "nier_automata",
+    "blue_eyes"
+  ]
+}