Add Checkpoints Gallery with per-checkpoint generation settings

- New Checkpoint model (slug, name, checkpoint_path, data JSON, image_path)
- sync_checkpoints() loads metadata from data/checkpoints/*.json and falls
  back to template defaults for models without a JSON file
- _apply_checkpoint_settings() applies per-checkpoint steps, CFG, sampler,
  base positive/negative prompts, and VAE (with dynamic VAELoader node
  injection for non-integrated VAEs) to the ComfyUI workflow
- Bulk Create from Checkpoints: scans Illustrious/Noob model directories,
  reads matching HTML files, uses LLM to populate metadata, falls back to
  template defaults when no HTML is present
- Gallery index with batch cover generation and WebSocket progress bar
- Detail page showing Generation Settings and Base Prompts cards
- Checkpoints nav link added to layout
- New data/prompts/checkpoint_system.txt LLM system prompt
- Updated README with all current galleries and file structure
- Also includes accumulated action/scene JSON updates, new actions, and
  other template/generator improvements from prior sessions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

data/actions/instant_loss_caught_il_nai_py.json

@@ -2,36 +2,35 @@
   "action_id": "instant_loss_caught_il_nai_py",
   "action_name": "Instant Loss Caught Il Nai Py",
   "action": {
-    "full_body": "character exhibiting immediate total defeat, body going completely limp and incapacitated",
-    "head": "head thrown back or slumped forward in unconsciousness, mouth falling open",
-    "eyes": "eyes rolled back (ahoge), empty eyes, or spiral eyes, indicating loss of consciousness",
-    "arms": "arms dangling uselessly at sides or floating limply if suspended",
-    "hands": "fingers loose and uncurled, wrists limp",
-    "torso": "posture collapsed, arching back or slumped over, defenseless",
-    "pelvis": "hips neutral or pushed forward due to limpness",
-    "legs": "knees buckled, legs giving way or dangling if lifted",
-    "feet": "feet relaxed, toes pointing down",
-    "additional": "drooling, tongue out, heavy breathing, flushed skin, sweat, mind break visual cues"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "MF"
+    "full_body": "lying, on_back, spread_legs, defeat",
+    "head": "blush, sweat, open_mouth, tongue_out, looking_at_viewer",
+    "eyes": "half_closed_eyes, tears",
+    "arms": "arms_at_sides, grabbing",
+    "hands": "clenched_hands",
+    "torso": "exposed_breasts, arching_back",
+    "pelvis": "legs_spread, pelvis_lift",
+    "legs": "spread_legs, knees_up",
+    "feet": "toes_curled",
+    "additional": "2koma, multiple_views, penis_shadow, comic"
   },
   "lora": {
     "lora_name": "Illustrious/Poses/Instant loss caught-IL_NAI_PY.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "Instant loss caught-IL_NAI_PY"
+    "lora_weight": 0.7,
+    "lora_triggers": "instant_loss, caught"
   },
   "tags": [
     "instant_loss",
-    "defeat",
-    "fainted",
-    "limp",
-    "unconscious",
-    "mind_break",
-    "eyes_rolled_back",
+    "caught",
+    "2koma",
+    "multiple_views",
+    "penis_shadow",
+    "lying",
+    "on_back",
+    "spread_legs",
+    "blush",
+    "open_mouth",
+    "sweat",
     "tongue_out",
-    "drooling",
-    "caught"
+    "defeat"
   ]
 }