feat: add calendar and contacts modules

modules/profiles/personal_calendar.nix

@@ -0,0 +1,52 @@
+{ lib
+, config
+, pkgs
+, ...
+}:
+
+with lib;
+let
+  cfg = config.my.profiles.personal;
+in
+{
+  options.my.profiles.personal.calendar = mkEnableOption "calendar";
+
+  config = mkIf cfg.contacts {
+    home-manager.users.moritz = {
+      programs.khal.enable = true;
+      programs.vdirsyncer.enable = true;
+      services.vdirsyncer.enable = true;
+      accounts.calendar = {
+        basePath = "Documents/Calendar";
+        accounts.personal = {
+          local = {
+            type = "filesystem";
+            fileExt = ".ics";
+          };
+          remote = {
+            passwordCommand = [ "cat" "/run/agenix/nextcloud" ];
+            url = "https://nextcloud.moritzboeh.me/remote.php/dav";
+            type = "caldav";
+            userName = "moritz";
+          };
+          primaryCollection = "personal";
+          khal.enable = true;
+          khal.type = "discover";
+          vdirsyncer.enable = true;
+          vdirsyncer.collections = [
+            "personal" # Personal
+            "einkaufsliste" # Einkaufsliste
+            "9b8be6f3-d85c-4c1e-b006-00910f56bf5d" # Tasks
+            "contact_birthdays" # Contact birthdays
+            "f71a1a0f-08c5-45de-84e8-e7f16b748ba5" # Uni
+            "32c96d6f-a575-48b1-949a-6ae548f7a779" # Work
+          ];
+        };
+      };
+    };
+    age.secrets.nextcloud = {
+      file = ../../secrets/nextcloud.age;
+      owner = "1000";
+    };
+  };
+}