fix: resolve TypeScript type errors in test files

- Add vitest/globals to tsconfig.json types array to provide type
  definitions for global test functions (describe, it, expect, vi)
- Fix vi.fn type parameter in useDirectorySettings.test.tsx from
  <[], Promise<string>> to <() => Promise<string>>
- Remove unused setMcpConfig import from MSW handlers
- Add type assertions for mock.calls access in McpFormModal tests
  to resolve union type inference issues

This ensures pnpm typecheck passes without errors while maintaining
test functionality with vitest globals: true configuration.

tsconfig.json

@@ -17,7 +17,8 @@
     "baseUrl": ".",
     "paths": {
       "@/*": ["src/*"]
-    }
+    },
+    "types": ["vitest/globals"]
   },
   "include": ["src/**/*", "tests/**/*"],
   "references": [{ "path": "./tsconfig.node.json" }]