Sync Nextcloud task lists via DAV; azos-core bump: dav module, org-roam to base

features/dav declares the Nextcloud CalDAV account (password from pass,
gated on the YubiKey like mail) for azos-core's new azos.dav module.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

features/dav/default.nix

@@ -0,0 +1,31 @@
+{...}: {
+  config.flake.modules.homeManager.dav = {
+    lib,
+    config,
+    pkgs,
+    ...
+  }: {
+    config = {
+      azos.dav.enable = true;
+
+      # Same smartcard gate as mail: the password comes from `pass`.
+      azos.dav.presenceCheckCommand = lib.mkIf config.azos.encryption.yubikey.enable "${pkgs.azos-card-present}/bin/azos-card-present";
+
+      accounts.calendar.accounts.nextcloud = {
+        remote = {
+          type = "caldav";
+          # Principal discovery from the DAV root resolves the account's
+          # user ID, which differs from the login name on this server.
+          url = "https://nextcloud.zakobar.com/remote.php/dav/";
+          userName = "aner";
+          passwordCommand = ["sh" "-c" "pass zakobar.com | head -1"];
+        };
+        vdirsyncer = {
+          enable = true;
+          collections = ["from a"];
+          itemTypes = ["VTODO"];
+        };
+      };
+    };
+  };
+}

home-manager/home.nix

@@ -17,6 +17,7 @@
     suiteModules.homeManager.lauretta
     suiteModules.homeManager.claude
     suiteModules.homeManager.hyprland
+    suiteModules.homeManager.dav
     suiteModules.homeManager.mail
     suiteModules.homeManager.mpris-proxy
     suiteModules.homeManager.nextcloud