Fix memory leaks: zombie Compressor processes and inherited shared buffers

[Cybis320]

Targets the OOM / swap-spiral failures seen on memory-tight stations.

Capture memory (BufferedCapture, Compression, QueuedPool, ConfigReader)

• New gst_queue_size config (default 100) drives the GStreamer queue/appsink max-buffers, previously hardcoded to 100. Lower it to shrink per-camera buffering on tight boxes. The buffer-fill % calc now uses it too.
• Daytime release: the shared compression buffers (~0.5 GB/array) are returned to the OS while idle in daylight (MADV_REMOVE, with DONTNEED fallback) instead of lingering in swap until night.
• MADV_DONTFORK on those buffers so GStreamer/RawFrameSaver grandchildren don't carry them.
• Leak fixes: QueuedPool now owns its Manager and exposes shutdownManager() (called after getResults() in StartCapture/DetectStarsAndMeteors/ExtractStars); Compressor reaps unjoined procs and os._exit()s its run-exit paths so lingering Manager proxy threads don't block shutdown.

MultiCam updater (GRMSUpdater.sh)

• New --reboot (always) / --reboot-if-needed (only when pending OS updates) flags; default unchanged. Stops stations cleanly before rebooting.
• --reboot-if-needed uses /var/run/reboot-required, falling back to running-vs-installed kernel.
• Requires passwordless sudo shutdown or the reboot is skipped with a warning. Stock Raspberry Pi OS already grants the default user blanket NOPASSWD sudo, so no setup is needed there. On hardened setups, grant just the shutdown command:

echo 'my_username ALL=(ALL) NOPASSWD: /usr/sbin/shutdown' | sudo tee /etc/sudoers.d/rms-reboot > /dev/null
sudo chmod 0440 /etc/sudoers.d/rms-reboot

For instance, this cron job checks for an RMS update daily, updates and restarts RMS if needed, and additionally reboots the machine if a reboot is required to complete an OS update:

0 19 * * * /home/<username>/source/RMS/Scripts/MultiCamLinux/GRMSUpdater.sh  --reboot-if-needed