All platform-specific paths and commands replaced with Linux equivalents:
- .git_path: Use system git instead of /Library/Developer/CommandLineTools
- start_server.sh: Use hostname -I instead of ipconfig
- AI_RULES.md line 18: Remove macOS path mandate
- PROJECT_ARCHITECTURE.md Section 7.5: Document Linux native approach
- SESSION_STATE.md: Update git binary reference
Ready for Ubuntu development, Docker testing, and standalone deployment.
