Wake the Asahi mic mapper on PipeWire events instead of polling every 2 s

[skuthus]

omarchy-asahi-mic.service --watch re-ran pw-dump plus several pactl queries every 2 seconds, forever, on every Apple Silicon machine. Measured on a MacBook Pro 14" (M1 Max), Omarchy 4.0.3-1, nothing playing:

audio stack CPU over 10 s (pipewire + pipewire-pulse + wireplumber + mapper)
before	142 jiffies — 14.2% of a core, constantly
after	3 jiffies — 0.3%

The stack never idled because the poll kept it awake.

What changed — bin/omarchy-audio-asahi-mic-map (+110 / −13)

1. supervise() sleeps on pactl subscribe and repairs only when something that can break the mapping happens: a sink, source, card or module appears or vanishes, a card or module changes, or the server changes (pipewire-pulse restart, default device switch).
2. Stream and client events are ignored, and so are sink/source change events: every stream start and stop emits those, and the mapping depends only on node existence, links and defaults.
3. A burst settles for 0.5 s so a hot-plug repairs once; a 5 s cap keeps a steady event stream from starving repair; a 10-minute backstop keeps the eventually-consistent behaviour the poll gave. That backstop is also what persists a gain change made between other events — the one thing that now waits up to 10 min instead of 2 s. omarchy-restart-audio --save-state still saves immediately.
4. A lost subscription (pipewire-pulse not up yet, or restarted) repairs once and resubscribes after 2 s — the old cadence, only while there is nothing to subscribe to.
5. SIGTERM unwinds through supervise so the subscriber child exits with the service.

Unit file, migration and the --save-state path are unchanged. supervise(operation, wait=None) keeps working for existing callers; the test injects wait.

Verified on hardware

1. Idle: the numbers above.
2. pactl load-module module-null-sink … → repair ran inside the settle window.
3. pactl unload-module <omarchy_asahi_mic> → sink rebuilt after ~500 ms.
4. paplay a 0.5 s clip → zero repairs triggered.
5. kill -TERM the watcher → no pactl subscribe left behind.

Tests

test/shell.d/asahi-mic-map-test.sh passes. New coverage: wake on device event, wake on server change, no wake on stream events, settle cap, lost subscription, missing subscriber.

To review in 2 minutes

Read Subscription.wait() (25 lines). Everything else is plumbing.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WHvo2RfghRcv7UoqFntuM9