Agents not removed from sidebar when closed — `prune_terminal`/`prune_stuck` never called + `/pane-exited` skips tracker update

[Morette]

Summary

Closed agents persist in the sidebar indefinitely. The only way to clear them is to fully close and reopen opensessions (server restart). Toggling the sidebar does not help.

Root causes

Bug 1 (primary): prune_terminal() and prune_stuck() are implemented but never called

packages/runtime-rs/src/tracker.rs has both pruning methods:

• prune_terminal — removes terminal-status agents (Done / Error / Interrupted / Stale) after TERMINAL_PRUNE_MS (5 min), skipping unseen and still-alive ones
• prune_stuck — removes Running / ToolRunning agents that have received no update past a configurable timeout and are not alive

Neither is called anywhere in apps/server-rs/src/lib.rs. The background loops (run_agent_watcher_loop, run_tmux_state_poll_loop) never invoke them, so the AgentTracker only grows — entries are never pruned until the server process restarts.

Bug 2 (contributing): /pane-exited hook handler ignores the agent tracker

apps/server-rs/src/lib.rs:1062 — the handler for the pane-exited tmux hook:

"/pane-exited" => {
    // kills orphaned sidebar panes, enforces width
    // returns None — no state broadcast, no tracker update
}

It does not call sync_agent_pane_presence() and returns None, so the sidebar is not refreshed when a pane exits. The next update only happens on the 2-second TMUX_STATE_POLL_MS tick.

Bug 3 (minor): /pane-died hook is installed but silently rejected

tmux_provider.rs installs a pane-died tmux hook alongside pane-exited, but is_ok_hook_path() only whitelists /pane-exited — not /pane-died. Requests for /pane-died are rejected before reaching the handler.

Expected fix

1. Call tracker.prune_terminal() and tracker.prune_stuck(timeout_ms) on each tick inside run_tmux_state_poll_loop or run_agent_watcher_loop
2. In the /pane-exited handler, call self.sync_agent_pane_presence() and return Some(self.snapshot_json()) to push an immediate update
3. Add /pane-died to is_ok_hook_path and handle it the same as /pane-exited

Environment

• opensessions latest (a383e9f)
• macOS, tmux

[rs545837]

Thanks for opening this, lemme take a look.