Silent Sentinel com.invictus.sentinel.plist Launch Daemon

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<!--
    com.invictus.sentinel.plist
    Install to: /Library/LaunchDaemons/com.invictus.sentinel.plist
    Load with:  sudo launchctl load /Library/LaunchDaemons/com.invictus.sentinel.plist
    Owner:      root:wheel, permissions 644

    KEY DECISIONS:

    ProcessType = Interactive
        Tells launchd to schedule this daemon at the highest QoS class
        available to background daemons. Combined with the in-script
        `renice -n -20`, this gives Sentinel two layers of priority:
        one at the launchd scheduling level, one at the BSD nice level.

    ThrottleInterval = 0
        By default launchd imposes a 10s throttle between restarts on
        crash. Setting to 0 removes this delay so Sentinel restarts
        immediately if it ever exits unexpectedly (e.g. OOM kill).
        Safe here because the script has its own sleep-based rate limiting.

    RunAtLoad = true
        Sentinel starts as soon as the plist is loaded, which on this
        LaunchDaemon path happens very early in the boot sequence —
        before most user-space services are running. This is as close
        to a "preboot hook" as launchd allows without kernel extensions.

    KeepAlive = true
        launchd will restart Sentinel if it ever exits. Combined with
        ThrottleInterval=0, this makes Sentinel effectively indestructible
        from user-space.

    AbandonProcessGroup = true
        When launchd stops the daemon (e.g. on shutdown), it won't wait
        for child processes (the ghost-eviction subshell, xargs children)
        to exit before proceeding. Prevents shutdown delays.

    NOTE ON "PREBOOT HOOKS":
        There is no OpenCore or EFI mechanism that can run BSD sysctls
        before the kernel boots — sysctls don't exist at that stage.
        The true "earliest possible" injection point for sysctl tunables
        on macOS is a LaunchDaemon with RunAtLoad=true at system boot,
        which is exactly what this plist achieves. The 10s sleep in the
        script is the only thing delaying injection, and it's necessary
        for OCLP kext stability on this hardware.
-->
<plist version="1.0">
<dict>

    <key>Label</key>
    <string>com.invictus.sentinel</string>

    <key>ProgramArguments</key>
    <array>
        <string>/bin/zsh</string>
        <string>/usr/local/bin/silent_sentinel.sh</string>
    </array>

    <!-- Start immediately at boot, before user session -->
    <key>RunAtLoad</key>
    <true/>

    <!-- Restart immediately on exit, no throttle delay -->
    <key>KeepAlive</key>
    <true/>
    <key>ThrottleInterval</key>
    <integer>0</integer>

    <!-- Highest QoS class available to LaunchDaemons -->
    <key>ProcessType</key>
    <string>Interactive</string>

    <!-- Don't block shutdown waiting for our subshells -->
    <key>AbandonProcessGroup</key>
    <true/>

    <!-- Logging — tail -f /var/log/sentinel.log to observe -->
    <key>StandardOutPath</key>
    <string>/var/log/sentinel.log</string>
    <key>StandardErrorPath</key>
    <string>/var/log/sentinel.log</string>

</dict>
</plist>