feat(comfyui): rewrite skill — official CLI + REST API, no third-party dependency

Complete rewrite of the ComfyUI skill to use:
- comfy-cli (official, Comfy-Org/comfy-cli) for lifecycle management:
  install, launch, stop, node management, model downloads
- Direct REST API + helper scripts for workflow execution:
  parameter injection, submission, monitoring, output download
- No dependency on comfyui-skill-cli or any unofficial tool

New files:
- SKILL.md: full rewrite with two-layer architecture, decision tree, pitfalls
- references/official-cli.md: complete comfy-cli command reference
- references/rest-api.md: all REST endpoints (local + cloud)
- references/workflow-format.md: API format spec, common nodes, param mapping
- scripts/extract_schema.py: analyze workflow → extract controllable params
- scripts/run_workflow.py: inject args, submit, poll, download outputs
- scripts/check_deps.py: check missing nodes/models against running server
- scripts/comfyui_setup.sh: full setup automation with official CLI

Removed:
- references/cli-reference.md (was for unofficial comfyui-skill-cli)
- references/api-notes.md (replaced by rest-api.md)

Addresses feedback from PR #17316 comment:
- Correct author attribution
- Remove references to unofficial OpenClaw project
- License field reflects hermes-agent repo (MIT)

optional-skills/creative/comfyui/scripts/comfyui_setup.sh

@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+# ComfyUI Setup — Install, launch, and verify using the official comfy-cli.
+# Usage: bash scripts/comfyui_setup.sh [--nvidia|--amd|--m-series|--cpu]
+#
+# Prerequisites: Python 3.10+, pip
+# What it does:
+#   1. Installs comfy-cli (if not present)
+#   2. Disables analytics tracking
+#   3. Installs ComfyUI + ComfyUI-Manager
+#   4. Launches server in background
+#   5. Verifies server is reachable
+
+set -euo pipefail
+
+GPU_FLAG="${1:---nvidia}"  # Default to NVIDIA
+
+echo "==> ComfyUI Setup"
+echo "    GPU flag: $GPU_FLAG"
+echo ""
+
+# Step 1: Install comfy-cli
+if command -v comfy >/dev/null 2>&1; then
+    echo "==> comfy-cli already installed: $(comfy -v 2>/dev/null || echo 'unknown version')"
+else
+    echo "==> Installing comfy-cli..."
+    pip install comfy-cli
+fi
+
+# Step 2: Disable tracking (avoid interactive prompt)
+echo "==> Disabling analytics tracking..."
+comfy --skip-prompt tracking disable 2>/dev/null || true
+
+# Step 3: Install ComfyUI
+if comfy which 2>/dev/null | grep -q "ComfyUI"; then
+    echo "==> ComfyUI already installed at: $(comfy which 2>/dev/null)"
+else
+    echo "==> Installing ComfyUI ($GPU_FLAG)..."
+    comfy --skip-prompt install $GPU_FLAG
+fi
+
+# Step 4: Launch in background
+echo "==> Launching ComfyUI in background..."
+comfy launch --background 2>/dev/null || {
+    echo "==> Background launch failed. Trying foreground check..."
+    echo "    You may need to run: comfy launch"
+    exit 1
+}
+
+# Step 5: Wait for server to be ready
+echo "==> Waiting for server..."
+MAX_WAIT=30
+ELAPSED=0
+while [ $ELAPSED -lt $MAX_WAIT ]; do
+    if curl -s http://127.0.0.1:8188/system_stats >/dev/null 2>&1; then
+        echo "==> Server is running!"
+        curl -s http://127.0.0.1:8188/system_stats | python3 -m json.tool 2>/dev/null || true
+        break
+    fi
+    sleep 2
+    ELAPSED=$((ELAPSED + 2))
+done
+
+if [ $ELAPSED -ge $MAX_WAIT ]; then
+    echo "==> Server did not start within ${MAX_WAIT}s."
+    echo "    Check logs with: comfy launch (foreground) to see errors."
+    exit 1
+fi
+
+echo ""
+echo "==> Setup complete!"
+echo "    Server: http://127.0.0.1:8188"
+echo "    Web UI: http://127.0.0.1:8188 (open in browser)"
+echo "    Stop:   comfy stop"
+echo ""
+echo "    Next steps:"
+echo "    - Download a model: comfy model download --url <URL> --relative-path models/checkpoints"
+echo "    - Run a workflow:   python3 scripts/run_workflow.py --workflow <file.json> --args '{...}'"