test: cover vite build config

[adliebe]

Summary

• Add focused Vitest coverage for the Vite client build configuration.
• Verify interface page entry discovery, output directory/manifest settings, hashed asset naming, manual chunks, public directory, and @interface alias wiring.
• Add worker-build coverage for SQL asset inclusion, Cloudflare dev port, Cloudflare worker external, and Hono worker build/dev plugins.

/claim #71

Validation

• pnpm test -- vite-build-config.test.ts --run -> 2 tests passed
• pnpm exec vitest run vite-build-config.test.ts -> 2 tests passed
• pnpm exec prettier --check vite-build-config.test.ts -> passed
• git diff --check -> passed
• pnpm test -- --run -> new vite-build-config.test.ts passed; full suite still has existing unrelated RLS failures in src/rls/index.test.ts (4 failures around SELECT/JOIN/subquery policy injection), consistent with the current baseline noted by other Improve test coverage with Vitest #71 coverage PRs.

Demo

Short terminal demo GIF: https://github.com/adliebe/starbasedb/releases/download/starbasedb-pr252-demo-20260527051412/starbasedb-vite-config-demo.gif