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/giantess_cunnilingus_illustrious.json

@@ -2,36 +2,36 @@
   "action_id": "giantess_cunnilingus_illustrious",
   "action_name": "Giantess Cunnilingus Illustrious",
   "action": {
-    "full_body": "giantess, size difference, recumbent, m-legs, lying on back, low angle view, from below",
-    "head": "pleasured expression, heavy blush, mouth open, head thrown back, panting",
-    "eyes": "half-closed eyes, rolling eyes, heart-shaped pupils, ahegao",
-    "arms": "arms spread, resting",
-    "hands": "hands grasping sheets, clenching",
-    "torso": "large breasts, heaving chest, arched back",
-    "pelvis": "legs spread wide, exposed pussy, wet",
-    "legs": "spread legs, bent knees, thick thighs",
-    "feet": "toes curled",
-    "additional": "cunnilingus, oral sex, licking, tongue, saliva, micro male, miniguy, shrunken partner, pov"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "MF"
+    "full_body": "A tall female giantess standing, often leaning back against a wall, while a much shorter male performs cunnilingus.",
+    "head": "Looking down, often laughing or with a happy/aroused expression.",
+    "eyes": "Looking down at partner.",
+    "arms": "Hands placed on the partner's head, pressing it into her crotch or grabbing their hair.",
+    "hands": "Hands upon another's head, holding head.",
+    "torso": "Leaning back slightly, often against a vertical surface.",
+    "pelvis": "Thrust forward or positioned for access.",
+    "legs": "Standing, legs apart or one leg lifted (leg lock).",
+    "feet": "Standing on ground.",
+    "additional": "Extreme size difference emphasized."
   },
   "lora": {
     "lora_name": "Illustrious/Poses/Giantess_Cunnilingus_Illustrious.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "Giantess_Cunnilingus_Illustrious"
+    "lora_weight": 0.8,
+    "lora_triggers": "giantess cunnilingus, tall_female, short_male"
   },
   "tags": [
-    "illustrious (azur lane)",
     "giantess",
     "cunnilingus",
-    "size difference",
-    "micro",
-    "low angle",
-    "m-legs",
-    "oral sex",
+    "standing_cunnilingus",
     "femdom",
-    "anime center"
+    "size_difference",
+    "tall_female",
+    "short_male",
+    "hands_on_another's_head",
+    "leaning_back",
+    "against_wall",
+    "laughing",
+    "looking_down",
+    "face_in_crotch",
+    "leg_lock"
   ]
 }