Remote Control can watch for session changes instead of only polling

What

Remote Control lets you reach a Claude Code session from another device. The part that talks to Anthropic's servers, the bridge, used to check for new work at fixed intervals, which is called polling.

• The bridge now has a sessionsWatch client. It gets a resume token from /v1/code/sessions?limit=1 and opens a stream of server-sent events (a connection where the server pushes updates) at /v1/code/sessions/watch, sending the last event it saw so it can pick up where it left off.
• A "sync" event marks the watcher as connected. "added" and "changed" events trigger an immediate check for work.
• While the watcher is connected, its own pacing replaces the fixed poll intervals.
• Four new settings in the bridge's server-supplied configuration control this: watch_sessions, watch_connected_poll_interval_ms, watch_fallback_poll_interval_ms and watch_session_end_window_ms.
• The watcher starts only when the configuration has watch_sessions set and other checks pass, and stops otherwise.

Why

When the watcher runs, Remote Control can notice new sessions sooner and ask the server for updates less often. Whether it runs depends on configuration sent from the server.