chore: speed up tests and update opencode models

vitest.unit.config.ts

@@ -1,4 +1,4 @@
-import { defineConfig, mergeConfig } from "vitest/config";
+import { defineConfig } from "vitest/config";
 import baseConfig from "./vitest.config.ts";
 
 const baseTest = (baseConfig as { test?: { include?: string[]; exclude?: string[] } }).test ?? {};
@@ -9,12 +9,11 @@ const include = baseTest.include ?? [
 ];
 const exclude = baseTest.exclude ?? [];
 
-export default mergeConfig(
-  baseConfig,
-  defineConfig({
-    test: {
-      include,
-      exclude: [...exclude, "src/gateway/**", "extensions/**"],
-    },
-  }),
-);
+export default defineConfig({
+  ...baseConfig,
+  test: {
+    ...baseTest,
+    include,
+    exclude: [...exclude, "src/gateway/**", "extensions/**"],
+  },
+});