refactor: reorganize server modules

- Moved each individual service definition into a dedicated `services/`
  directory under every server module (e.g.
`modules/servers/bragi/services/`).
- Updated the corresponding `default.nix` files to import the renamed
  service modules from the new location.
- Applied the same changes across all server modules, ensuring
  the API and import paths remain consistent.

modules/servers/tyr/services/syncthing.nix

@@ -0,0 +1,29 @@
+{
+  services.syncthing = {
+    enable = true;
+    openDefaultPorts = true;
+    guiAddress = "0.0.0.0:8384";
+  };
+
+  services.restic.backups = {
+    local.paths = ["/var/lib/syncthing"];
+    server.paths = ["/var/lib/syncthing"];
+  };
+
+  services.traefik.dynamicConfigOptions.http = {
+    services.syncthing.loadBalancer.servers = [
+      {
+        url = "http://localhost:8384";
+      }
+    ];
+
+    routers.syncthing = {
+      rule = "Host(`syncthing.home.cronyakatsuki.xyz`)";
+      tls = {
+        certResolver = "porkbun";
+      };
+      service = "syncthing";
+      entrypoints = "websecure";
+    };
+  };
+}