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>

models/vllm/requirements.txt

@@ -1,13 +1,4 @@
 # vLLM Text Generation Service Dependencies
 
-# vLLM engine
+# vLLM engine (will install compatible torch, transformers, etc.)
 vllm==0.6.4.post1
-
-# PyTorch (required by vLLM)
-torch==2.1.0
-
-# Transformers (for model loading)
-transformers==4.36.0
-
-# Additional dependencies
-accelerate==0.25.0