Implement Basic Session Management

[LittleCoinCoin]

Description:
Create basic session management system for organizing chat sessions and generated files.

Acceptance Criteria:

• Session directory structure automatically created. For example: ~/.hatch/sessions/session_YYYYMMDD_HHMMSS/
• Metadata tracking including settings used, start/end time, and session summary
  • Needs more thinking
• File organization with subdirectories: output/, context_files/, citations.json
• Basic session restoration capability to resume interrupted sessions
• Citation tracking per session with automatic aggregation
• Session cleanup utilities for managing disk space

Dependencies:

• Requires Issue Implement Modular Settings Architecture #12