fix(build): also exclude src/test/** from production tsc check

The test setup file (src/test/setup.ts) imports vitest and
@testing-library/*, so it needs to be excluded alongside test files.

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

tsconfig.json

@@ -27,6 +27,6 @@
     }
   },
   "include": ["src"],
-  "exclude": ["src/**/*.test.ts", "src/**/*.test.tsx"],
+  "exclude": ["src/**/*.test.ts", "src/**/*.test.tsx", "src/test/**"],
   "references": [{ "path": "./tsconfig.node.json" }]
 }