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/multiview_oralsex.json

@@ -2,33 +2,33 @@
   "action_id": "multiview_oralsex",
   "action_name": "Multiview Oralsex",
   "action": {
-    "full_body": "multiple views of a character displayed in a grid or sequence, showing different angles of a kneeling pose",
-    "head": "tilted slightly upward or forward, varying by angle, mouth slightly open or neutral",
-    "eyes": "focused upward or closed, depending on the specific view",
-    "arms": "reaching forward or resting on a surface",
-    "hands": "gesturing or holding onto a support",
-    "torso": "leaning forward, back slightly arched",
-    "pelvis": "positioned low, kneeling grounded stance",
-    "legs": "knees bent on the ground, shins flat against the surface",
-    "feet": "toes supporting or flat, visible in rear views",
-    "additional": "character sheet style, white or simple background to emphasize the pose analysis"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "MF"
+    "full_body": "kneeling, multiple_views",
+    "head": "licking, saliva, open_mouth, tongue_out",
+    "eyes": "looking_at_penis",
+    "arms": "arms_down",
+    "hands": "on_legs",
+    "torso": "leaning_forward",
+    "pelvis": "kneeling",
+    "legs": "kneeling",
+    "feet": "toes",
+    "additional": "fellatio, penis, testicles, close-up"
   },
   "lora": {
     "lora_name": "Illustrious/Poses/multiview_oralsex.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "multiview_oralsex"
+    "lora_weight": 0.9,
+    "lora_triggers": "multi_oralsex, oral, multiple_views, kneeling, testicles, saliva, licking, penis"
   },
   "tags": [
-    "multiview",
-    "character sheet",
-    "reference sheet",
+    "multiple_views",
+    "fellatio",
     "kneeling",
-    "leaning forward",
-    "multiple angles",
-    "pose check"
+    "saliva",
+    "licking",
+    "penis",
+    "testicles",
+    "close-up",
+    "open_mouth",
+    "tongue_out",
+    "leaning_forward"
   ]
 }