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/goblin_sucking_boobs_illustrious.json

@@ -2,33 +2,30 @@
   "action_id": "goblin_sucking_boobs_illustrious",
   "action_name": "Goblin Sucking Boobs Illustrious",
   "action": {
-    "full_body": "size difference, intimate interaction, a small goblin clinging to the torso of a larger female character",
-    "head": "looking down, expression of pleasure or surprise, heavy blush, saliva",
-    "eyes": "half-closed eyes, heart-shaped pupils, looking at goblin",
-    "arms": "cradling the goblin, holding the goblin's head, pressing breast to mouth",
-    "hands": "fingers spread, holding the creature, squeezing breast",
-    "torso": "exposed breasts, breast sucking, nipple stimulation, arching back",
-    "pelvis": "slightly pushed forward or seated pose",
-    "legs": "standing or sitting, relaxed stance",
-    "feet": "toes curled (if visible)",
-    "additional": "monster, goblin, green skin, pointy ears, height difference, nursing, lactation"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "MF"
+    "full_body": "1girl with a small goblin creature clinging to her chest",
+    "head": "goblin's head buried in cleavage or mouth attached to nipple",
+    "eyes": "girl looking down at the goblin or closed in sensation",
+    "arms": "goblin grabbing the breasts or clinging to the torso",
+    "hands": "goblin's hands kneading or holding the breasts",
+    "torso": "exposed breasts being suckled",
+    "pelvis": "n/a",
+    "legs": "n/a",
+    "feet": "n/a",
+    "additional": "size difference between the large female character and the small goblin"
   },
   "lora": {
     "lora_name": "Illustrious/Poses/Goblin_sucking_boobs_Illustrious.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "Goblin_sucking_boobs_Illustrious"
+    "lora_weight": 0.8,
+    "lora_triggers": "goblin breastfeeding, goblin, breast sucking"
   },
   "tags": [
     "goblin",
-    "breast sucking",
-    "size difference",
+    "breast_sucking",
+    "breastfeeding",
     "monster",
-    "duo",
     "lactation",
-    "nsfw"
+    "1girl",
+    "monster_boy",
+    "size_difference"
   ]
 }