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/thor/services/changedetection-io.nix

@@ -0,0 +1,30 @@
+{...}: {
+  services.changedetection-io = {
+    enable = true;
+    playwrightSupport = true;
+    baseURL = "https://changedetection.cronyakatsuki.xyz";
+    behindProxy = true;
+  };
+
+  services.traefik.dynamicConfigOptions.http = {
+    services.changedetection.loadBalancer.servers = [
+      {
+        url = "http://localhost:5000";
+      }
+    ];
+
+    routers.changedetection = {
+      rule = "Host(`changedetection.cronyakatsuki.xyz`)";
+      tls = {
+        certResolver = "porkbun";
+      };
+      service = "changedetection";
+      entrypoints = "websecure";
+    };
+  };
+
+  services.restic.backups = {
+    local.paths = ["/var/lib/changedetection-io"];
+    server.paths = ["/var/lib/changedetection-io"];
+  };
+}