Alert on tmux output while its terminal is unfocused

tmux only raises an activity flag for windows that are not currently
selected, so a long-running command in the window you left selected --
the common case, since you switch away by moving your Hyprland focus
elsewhere rather than by selecting another tmux window -- finished
silently and the indicator never lit.

Windows now also count as waiting when they are selected in an attached
client, every client showing them is unfocused, and their window_activity
is newer than an @omarchy_unfocused_activity watermark. The watermark is
stamped by a new `track` subcommand wired to client-focus-in/out and the
existing select-window hooks, so it records where attention last was.
The hooks pass #{window_id} and #{window_activity} as arguments, which
tmux expands when the hook fires; run-shell -b would otherwise let output
arriving during the handoff be swallowed by the new watermark. The focus
hooks take index 100 to leave a user's own bindings alone.

That state has no hook of its own, so it needs polling to be noticed.
The probe therefore moves out of the indicator and into a service plugin,
alongside nightlight and battery. A bar surface exists per monitor and
each one instantiates every indicator twice, once per block, so a timer
on the indicator meant a shell-out per instance per tick -- four probe
processes every three seconds on a two-monitor machine, forever. One
service polls for the whole shell instead.

Sharing the state also fixes what per-instance polling would have papered
over: each indicator used to own its own count, so a timer-driven update
only refreshed the bar it ran on and left the other monitors stale.
Refreshes still arrive over the existing indicator broadcast, which now
coalesces into a single run no matter how many bars relay it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018CC9kSQv8ZEogaxDoeKBzL

migrations/1784955584.sh

@@ -0,0 +1,17 @@
+echo "Track tmux output while its terminal is unfocused"
+
+tmux_config="$HOME/.config/tmux/tmux.conf"
+
+if [[ -f $tmux_config ]] && ! grep -q 'client-focus-out\[100\].*omarchy-tmux-alert track' "$tmux_config"; then
+  sed -i \
+    -e 's|^set-hook -g after-select-window .*|set-hook -g after-select-window '"'"'run-shell -b "omarchy-tmux-alert track #{window_id} #{window_activity}"'"'"'|' \
+    -e 's|^set-hook -g client-session-changed .*|set-hook -g client-session-changed '"'"'run-shell -b "omarchy-tmux-alert track #{window_id} #{window_activity}"'"'"'|' \
+    "$tmux_config"
+
+  cat >>"$tmux_config" <<'EOF'
+set-hook -g client-focus-out[100] 'run-shell -b "omarchy-tmux-alert track #{window_id} #{window_activity}"'
+set-hook -g client-focus-in[100] 'run-shell -b "omarchy-tmux-alert track #{window_id} #{window_activity}"'
+EOF
+
+  omarchy-restart-tmux
+fi