Add ComfyUI Desktop workflow integration

Summary

Add a BlenderMCP integration for running user-provided ComfyUI Desktop workflows locally and importing their 3D results into Blender.

Scope

• Configure and verify a ComfyUI Desktop API endpoint
• Load workflows exported in API format
• Support explicit node input overrides and optional input-image upload
• Submit workflows and poll prompt history or queue state
• Discover and import GLB, GLTF, OBJ, FBX, STL, and PLY outputs
• Add Blender UI settings, MCP tools, documentation, and regression tests

Acceptance criteria

• Disabled or unreachable ComfyUI instances return a clear status
• API-format workflows can be submitted and return a prompt ID
• Completed, failed, cancelled, running, and queued states are reported
• Returned 3D output references are validated before download and import
• Existing integrations remain unaffected and automated tests pass