Volume lock file now stores {pid}:{volume}:{muted} instead of "1":
- Allows recovery of saved volume state if the holder is SIGKILLed
- On stale lock detection (holder PID not alive), inherit saved volume state
and take ownership — prevents permanent volume loss and infinite lockout
PAM module DEFAULT_PATH now baked in at build time via AHFAIL_LIBDIR env var
passed by Meson, fixing the wrong path on multiarch Debian/Ubuntu where libdir
is /usr/lib/x86_64-linux-gnu rather than /usr/lib.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
On the first failed unlock attempt, save the current system volume and
mute state then set volume to maximum unmuted; restore on g_module_unload.
A lock file under XDG_RUNTIME_DIR prevents double-acquisition when
multiple gtklock windows are active.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
