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/caught_masturbating_illustrious.json

@@ -2,39 +2,37 @@
   "action_id": "caught_masturbating_illustrious",
   "action_name": "Caught Masturbating Illustrious",
   "action": {
-    "full_body": "character receiving a sudden shock while in a private moment of self-pleasure, body freezing or jerking in surprise",
-    "head": "face flushed red with deep blush, expression of pure panic and embarrassment, mouth gaped open in a gasp",
-    "eyes": "wide-eyed stare, pupils dilated, locking eyes with the intruder (viewer)",
-    "arms": "shoulders tensed, one arm frantically trying to cover the chest or face, the other halted mid-motion near the crotch",
-    "hands": "one hand stopping mid-masturbation typically under skirt or inside panties, other hand gesturing to stop or hiding face",
-    "torso": "leaning back onto elbows or pillows, clothing disheveled, shirt lifted",
-    "pelvis": "hips exposed, underwear pulled down to thighs or ankles, vulva accessible",
-    "legs": "legs spread wide in an M-shape or V-shape, knees bent, trembling",
-    "feet": "toes curled tightly in tension",
-    "additional": "context of an intruded private bedroom, messy bed sheets, atmosphere of sudden discovery and shame"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "F"
+    "full_body": "standing in doorway, confronting viewer",
+    "head": "looking down or at viewer, surprised expression, blushing",
+    "eyes": "wide open, looking away or at penis",
+    "arms": "arms at sides or covering mouth",
+    "hands": "relaxed or raised in shock",
+    "torso": "facing viewer",
+    "pelvis": "standing straight",
+    "legs": "standing, legs together",
+    "feet": "standing on floor",
+    "additional": "male pov, male masturbation in foreground, open door background"
   },
   "lora": {
     "lora_name": "Illustrious/Poses/Caught_Masturbating_ILLUSTRIOUS.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "Caught_Masturbating_ILLUSTRIOUS"
+    "lora_weight": 0.75,
+    "lora_triggers": "caught, male pov, male masturbation, girl walking in door, standing in doorway"
   },
   "tags": [
+    "pov",
+    "male_masturbation",
+    "penis",
+    "erection",
+    "walk-in",
     "caught",
-    "masturbation",
-    "embarrassed",
-    "blush",
+    "doorway",
+    "open_door",
+    "standing",
     "surprised",
-    "open mouth",
-    "looking at viewer",
-    "panties down",
-    "hand in panties",
-    "skirt lift",
-    "sweat",
-    "legs spread",
-    "panic"
+    "blush",
+    "looking_at_penis",
+    "looking_at_viewer",
+    "wide_shot",
+    "indoors"
   ]
 }