Unknown control message types silently ignored — no default handler

[d0ugal]

Summary

The daemon handler's message type switch has no `default` branch. A typo, stale client, or future client talking to an older daemon gets no response and can block indefinitely waiting for a control reply.

Suggested Fix

Add a default case that returns an error response naming the unsupported message type.

Found by: Codex (tribunal audit round 2 — finding #7)

Related: #50 (protocol version validation)

[d0ugal]

Fixed in current code — closing. The daemon control-message switch now has a default case that replies with an explicit error naming the unsupported type (internal/daemon/handler.go:~1255: sendControl("error", protocol.ErrorMsg{Message: "unsupported control message: " + msg.Type})), so clients no longer block waiting on a response that never comes.