[DRAFT] Add a memory mode backed by ClickHouse

[Ryado]

⚠️ This is an experiment and not ready to be merged.

This PR introduces experimental memory management tools that allow storing and retrieving key-value data using ClickHouse as the backend storage.

New Tools Added

• save_memory: Store user-provided information as key-value pairs
• get_memories_titles: Retrieve all memory keys/titles with timestamps
• get_memory: Retrieve all memory entries matching a specific key
• get_all_memories: Retrieve all saved memories (use with caution for large datasets)
• delete_memory: Delete all memory entries matching a specific key

Implementation Details

• Memory data is stored in a user_memory table with automatic timestamps
• Tools are conditionally registered based on CLICKHOUSE_MEMORY environment variable
• Uses existing ClickHouse write query functionality for persistence
• Includes comprehensive test coverage for all memory operations
• Follows existing error handling patterns with structured responses

screen_record.mp4