A power cut makes the recordings drive's fsck slow, so the mount can
appear tens of seconds after nextnvr starts. The recorders then hit the
unmounted, root-owned mountpoint, failed mkdir, and exited permanently —
recording stayed dead until a manual restart.
- recorder: on mkdir failure, log and retry every 15s instead of exiting,
so recording resumes once storage returns
- storage: add waitForStorage() and call it before the writers start, so
startup waits (up to 120s) for the recordings dir to be present and
writable; live view still starts if storage never appears
A stalled RTSP stream (TCP connection alive but no data) made the recorder's ffmpeg processes block forever on read(). The -t 300 flag only bounds by input timestamps, not wall-clock, so it never fired and the recorder loop never started the next segment.
Add -rw_timeout (10s socket I/O timeout) so ffmpeg exits on a stalled stream and the existing retry loop reconnects automatically.
