Create the first interactive TUI client for chatting with an agent session.

Acceptance criteria:

• TUI can connect to the local daemon.
• TUI can start or attach to a session.
• Transcript view displays session events.
• Input editor accepts user messages.
• Assistant responses render incrementally while streaming.
• Tool calls and results have clear visual representation.
• Basic keyboard handling works.
• TUI remains responsive during streaming and tool execution.