refactor: clean Docker files and restore standalone model services

- Remove all Docker-related files (Dockerfiles, compose.yaml)
- Remove documentation files (README, ARCHITECTURE, docs/)
- Remove old core/ directory (base_service, service_manager)
- Update models.yaml with correct service_script paths (models/*/server.py)
- Simplify vLLM requirements.txt to let vLLM manage dependencies
- Restore original standalone vLLM server (no base_service dependency)
- Remove obsolete vllm/, musicgen/, flux/ directories

Process-based architecture is now fully functional on RunPod.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

vllm/requirements.txt

@@ -1,4 +0,0 @@
-vllm==0.6.4.post1
-fastapi==0.104.1
-uvicorn[standard]==0.24.0
-pydantic==2.5.0