Address all review feedback: UUID from queue, no logs/, config-based summary prompt, file-based requests

- UUID assigned by queue side (not generated in context manager)
- Remove logs/ directory, use contexts/ at root
- Move summary prompt to config.yaml
- Remove implementation phases chapter (not needed for spec)
- Detail all LLMClient changes (OpenAI, Ollama, LMStudio)
- Implement file-based requests for OpenAI (request.json) for memory optimization
- Add request.json temporary file for OpenAI HTTP requests
- Update all processing flows to reflect UUID from queue

Co-authored-by: notfolder <20558197+notfolder@users.noreply.github.com>

Author: Copilot