Add storage keepalive (upholds) across services, Nextcloud cron, disable Nextcloud PHP JIT

Requires= doesn't restart a service once its required mount comes back after
a USB disconnect/remount, so a dedicated storage-keepalive unit now Upholds=
every storage-dependent service to bring it back automatically. Also adds the
missing Nextcloud cron.php timer (background jobs were never triggered), and
disables opcache.jit in the Nextcloud container — PHP 8.4's JIT was
miscompiling OC\Config\UserConfig::getValueBool(), crashing every
session-bootstrapping request with a bogus strtolower() TypeError.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

modules/services/nextcloud.nix

@@ -49,6 +49,19 @@ let
         MaxConnectionsPerChild 500
     </IfModule>
   '';
+
+  # PHP 8.4's JIT miscompiles OC\Config\UserConfig::getValueBool() on this
+  # image, corrupting the type of the value passed to strtolower() and
+  # throwing "Argument #1 ($string) must be of type string, string given"
+  # on every request that bootstraps a user session (confirmed by disabling
+  # JIT live on 2026-10-08: the crash stopped immediately). Not an app or
+  # data bug — getTypedValue()'s `: string` return type and
+  # decryptSensitiveValue()'s `string &$value` by-ref param both independently
+  # guarantee the value is already a real string under strict_types=1 by the
+  # time strtolower() rejects it.
+  phpDisableJitConfig = pkgs.writeText "zzz-disable-jit.ini" ''
+    opcache.jit=0
+  '';
 in
 {
   options.homey.nextcloud = {
@@ -158,6 +171,8 @@ in
         "${nextcloudCustomConfig}:/var/www/html/config/zakobar.config.php:ro"
         # Apache MPM limits (caps concurrent PHP processes / disk writers)
         "${apacheMpmConfig}:/etc/apache2/mods-available/mpm_prefork.conf:ro"
+        # Disable JIT — see phpDisableJitConfig comment above for why.
+        "${phpDisableJitConfig}:/usr/local/etc/php/conf.d/zzz-disable-jit.ini:ro"
       ];
 
       extraOptions = [
@@ -210,6 +225,8 @@ in
     # UID 33 = www-data in the Nextcloud container
     # UID 999 = postgres — must own the db dir (creates files directly in it)
     # -----------------------------------------------------------------------
+    homey.storage.upholds = [ "podman-nextcloud-postgres.service" "podman-nextcloud.service" ];
+
     homey.storage.extraDirs = [
       { path = "nextcloud"; }
       { path = "nextcloud/html";    user = "33";  group = "33"; }