chore: speed up tests and update opencode models

vitest.extensions.config.ts

@@ -0,0 +1,14 @@
+import { defineConfig } from "vitest/config";
+import baseConfig from "./vitest.config.ts";
+
+const baseTest = (baseConfig as { test?: { exclude?: string[] } }).test ?? {};
+const exclude = baseTest.exclude ?? [];
+
+export default defineConfig({
+  ...baseConfig,
+  test: {
+    ...baseTest,
+    include: ["extensions/**/*.test.ts"],
+    exclude,
+  },
+});