fix: resolve $hatk alias in tests via Node.js module hooks
scanServerDir uses raw import() which bypasses Vite's resolve.alias.
Register a Node.js module resolve hook in createTestContext so $hatk
resolves to hatk.generated.ts in all contexts.
Also adds resolve.alias in the vite plugin for dev/build consistency.
Bumps to 0.0.1-alpha.27.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>