manatee: Add bluetooth reset handling

hosts/manatee/modules/home-assistant/default.nix

@@ -6,6 +6,60 @@
 }:
 let
   nginxEnabled = config.mod.nginx.enable;
+
+  script = pkgs.writeShellScript "bt-reset" ''
+    set -euo pipefail
+    export PATH="${
+      lib.makeBinPath [
+        pkgs.bluez
+        pkgs.util-linux
+        pkgs.kmod
+        pkgs.gnugrep
+        pkgs.coreutils
+      ]
+    }"
+
+    logger -t bt-reset "Starting Bluetooth adapter reset..."
+
+    # Exit early if the adapter is already present and running
+    if hciconfig hci0 2>/dev/null | grep -q "UP RUNNING"; then
+      logger -t bt-reset "hci0 is already UP RUNNING — nothing to do"
+      exit 0
+    fi
+
+    # If hci0 exists but isn't UP, try bringing it up
+    if hciconfig hci0 2>/dev/null; then
+      logger -t bt-reset "hci0 exists but not running — bringing it up"
+      hciconfig hci0 up || true
+      sleep 2
+
+      if hciconfig hci0 2>/dev/null | grep -q "UP RUNNING"; then
+        logger -t bt-reset "hci0 is UP now"
+        systemctl restart bluetooth.service
+        logger -t bt-reset "bluetooth.service restarted — done"
+        exit 0
+      fi
+    fi
+
+    # Hard reset: reload the btusb kernel module (works for USB adapters)
+    logger -t bt-reset "hci0 missing — reloading btusb module..."
+    modprobe -r btusb 2>/dev/null || true
+    sleep 3
+    modprobe btusb
+    sleep 3
+
+    if hciconfig hci0 2>/dev/null; then
+      hciconfig hci0 up
+      logger -t bt-reset "hci0 restored after module reload"
+    else
+      logger -t bt-reset "ERROR: hci0 not found after module reload"
+      exit 1
+    fi
+
+    # Restart the bluetooth systemd service so bluetoothd picks up the adapter
+    systemctl restart bluetooth.service
+    logger -t bt-reset "bluetooth.service restarted — done"
+  '';
 in
 {
   hardware.bluetooth.enable = true;
@@ -57,9 +111,48 @@ in
         };
       };
     };
+
+    # Trigger reset via udev when hci0 disappears
+    udev.extraRules = ''
+      ACTION=="remove", SUBSYSTEM=="bluetooth", KERNEL=="hci0", \
+        TAG+="systemd", ENV{SYSTEMD_WANTS}+="bt-reset.service"
+    '';
   };
 
-  systemd.user = {
+  systemd = {
+    services = {
+      # Trigger reset on bluetoothd failure
+      bluetooth = {
+        unitConfig.OnFailure = [ "bt-reset.service" ];
+      };
+
+      bt-reset = {
+        description = "Reset Bluetooth adapter";
+        after = [ "bluetooth.service" ];
+
+        serviceConfig = {
+          Type = "oneshot";
+          ExecStart = script;
+
+          Restart = "on-failure";
+          RestartSec = "10s";
+          StartLimitIntervalSec = "120";
+          StartLimitBurst = 3;
+        };
+      };
+    };
+
+    timers.bt-reset = {
+      description = "Periodically reset Bluetooth adapter";
+      wantedBy = [ "timers.target" ];
+      timerConfig = {
+        OnBootSec = "5min"; # first run 5 min after boot
+        OnUnitActiveSec = "4h"; # then every 4 hours
+        RandomizedDelaySec = "5min";
+      };
+    };
+
+    user = {
       timers = {
         "update-hetzner-ha-dns" = {
           unitConfig = {
@@ -125,6 +218,7 @@ in
         };
       };
     };
+  };
 
   age = {
     secrets = {