[DO NOT MERGE] Add dynamic partner nodes executor

[huntcsg]

Summary

Adds a generic, provider-agnostic executor for dynamically-loaded partner nodes from comfy-api.

How It Works

1. On startup, fetches node definitions from comfy-api's /object_info endpoint
2. Creates ComfyNode classes dynamically from the schema (inputs, outputs, category, etc.)
3. On execution, serializes inputs per config (e.g., images to base64)
4. POSTs to comfy-api's /proxy/dynamic/{node_id} endpoint
5. Deserializes response bytes to appropriate output type (video/image/audio)

Key Design

The Python code is completely provider-agnostic:

• No hardcoded API endpoints or model names
• No provider-specific input transformations
• All behavior driven by proxy config from /object_info

All provider-specific logic lives in comfy-api (Go):

• Model name mapping (e.g., "LTX-2 (Pro)" → "ltx-2-pro")
• API authentication and request formatting
• Polling for async APIs
• Response handling

Related

• comfy-api PR: https://github.com/Comfy-Org/comfy-api/pull/793

API Node PR Checklist

Scope

• Is API Node Change

Pricing & Billing

• Need pricing update
• No pricing update

If Need pricing update:

• Metronome rate cards updated
• Auto‑billing tests updated and passing

QA

• QA done
• QA not required

Comms

• Informed Kosinkadink