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/princess_carry_fellatio_r1.json

@@ -2,36 +2,29 @@
   "action_id": "princess_carry_fellatio_r1",
   "action_name": "Princess Carry Fellatio R1",
   "action": {
-    "full_body": "duo, 1boy, 1girl, standing, lift, the male character is standing and holding the female character in his arms off the ground, the female character is performing oral sex while being carried",
-    "head": "female head positioned at male crotch level, face touching penis, cheek bulging, eyes looking up or closed",
-    "eyes": "upturned eyes, half-closed eyes, or heart-shaped pupils",
-    "arms": "male arms wrapping around female back and under knees (cradle hold/princess carry), female hands holding male hips or guiding penis",
-    "hands": "hands on hips, gripping clothing",
-    "torso": "female body curled inward towards male, male torso upright and leaning slightly back to support weight",
-    "pelvis": "male hips thrust forward, female pelvis suspended in air adjacent to male waist",
-    "legs": "male legs standing apart for balance, female legs bent at knees and supported by male arm, feet dangling",
-    "feet": "toes pointing down or curled",
-    "additional": "height difference, suspended in air, gravity defiance, fluid motion"
-  },
-  "participants": {
-    "solo_focus": "true",
-    "orientation": "MF"
+    "full_body": "Female character standing upright, holding a male character horizontally across her chest in a bridal carry (princess carry) position.",
+    "head": "Looking down towards the male's groin area, mouth open or engaged in fellatio.",
+    "eyes": "Focused downwards on the male.",
+    "arms": "Curved under the male's back and knees, supporting his full weight.",
+    "hands": "Firmly gripping the male's body or legs for support.",
+    "torso": "Strong posture, leaning slightly back to counterbalance the weight.",
+    "pelvis": "Squared forward, stable base.",
+    "legs": "Standing with a wide, stable stance to support the weight.",
+    "feet": "Planted firmly on the ground.",
+    "additional": "The female is typically depicted as larger/taller/stronger than the male (size difference); male is often nude while female is clothed."
   },
   "lora": {
     "lora_name": "Illustrious/Poses/Princess_Carry_Fellatio_r1.safetensors",
-    "lora_weight": 1.0,
-    "lora_triggers": "Princess_Carry_Fellatio_r1"
+    "lora_weight": 0.85,
+    "lora_triggers": "Princess Carry Fellatio, Female carrying male, hetero, clothed female, nude male, size difference, larger female, from side"
   },
   "tags": [
-    "princess carry",
+    "princess_carry",
+    "carrying",
     "fellatio",
     "standing",
-    "lifted by other",
-    "carrying",
-    "standing fellatio",
-    "oral",
-    "duo",
-    "holding up",
-    "nsfw"
+    "size_difference",
+    "tall_female",
+    "hetero"
   ]
 }