Release v0.6.0

Added

• /revert command to restore conversation to any previous message state
• 5 revert modes: full restore (code + conversation), conversation only, code only, summarize from point, or cancel
• Paginated history browser showing last 50 messages with inline keyboard navigation
• Priority handling for /revert: bypasses message queue limit and cancels active operations
• Interactive mode selection via Telegram inline buttons
• Conversation state restoration by truncating SDK JSONL files to selected message

Changed

• Updated documentation (README.md, README-zh.md) with /revert usage examples
• Improved button text consistency: changed "Never mind" to "Cancel"