feat(cli): add 'chrome-use daemon restart|status' to reset stuck session state

A mid-session 'chrome-use upgrade' (or a crashed worker) can leave per-session
daemons holding stale/cross-leaked tab handles, and the only fix was hunting
PIDs with pgrep/kill. Add a first-class command:

- 'daemon restart' kills every session daemon worker (SIGTERM→SIGKILL +
  sidecar cleanup) but leaves the Chrome-launched __nm-host bridge alone, so
  the extension relay stays up — the next command spins a fresh, clean daemon
  against the same live Chrome. Closes no tabs.
- 'daemon status' lists running session daemons (pid + version) and relay state.

Wires connection::restart_all_daemons(), skips the command in the update-notify
nag, documents it in --help and the core skill. Unit tests cover the empty case
and a live-session kill (spawns a real child, asserts it's reaped + sidecars
cleaned). Issue #20.

skill-data/core/SKILL.md

@@ -501,6 +501,22 @@ the same browser's existing targets, so a second session's first `open` can
 navigate a sibling's tab. For concurrent agents on one real Chrome, use the
 extension (each with a distinct `--session`), not raw `--cdp`.
 
+### Reset stuck daemon state
+
+Each session runs a background daemon worker that holds the page handles. If a
+session starts misbehaving — commands hit the wrong tab, refs/handles look stale,
+or you upgraded `chrome-use` mid-session and old workers linger — restart the
+daemons instead of hunting PIDs with `pgrep`/`kill`:
+
+```bash
+chrome-use daemon status     # list running session daemons (+ relay state)
+chrome-use daemon restart    # kill every session daemon worker
+```
+
+`daemon restart` leaves the extension's native-messaging bridge (`__nm-host`)
+alone, so the relay to your live Chrome stays up — the next command just spins up
+a fresh, clean daemon against the same browser. It does **not** close any tabs.
+
 ### Mock network requests
 
 ```bash