update zed config to fix deprecation warnings

home/modules/zed/default.nix

@@ -84,7 +84,6 @@ in
         };
         agent = {
           enabled = true;
-          version = "2";
           default_model = {
             provider = "zed.dev";
             model = "claude-sonnet-4-thinking";
@@ -202,10 +201,13 @@ in
         };
         context_servers = {
           browser-tools-context-server = {
+            source = "extension";
+            settings = {
               npx_command = "${pkgs.nodejs}/bin/npx";
             };
           };
         };
+      };
       userKeymaps = [
         {
           context = "VimControl && !menu";