Use basic vitest config for unit tests

Unit tests don't need Workers runtime - use standard vitest.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: hudgeon

vitest.config.ts

@@ -1,12 +1,8 @@
-import { defineWorkersConfig } from '@cloudflare/vitest-pool-workers/config'
+import { defineConfig } from 'vitest/config'
 
-export default defineWorkersConfig({
+export default defineConfig({
   test: {
     globals: true,
-    poolOptions: {
-      workers: {
-        wrangler: { configPath: './wrangler.toml' },
-      },
-    },
+    include: ['**/*.test.ts'],
   },
 })