fix: restore Bun CLI builds with chromium-bidi

[jairad26]

Summary

• add chromium-bidi as a direct dependency so Bun can resolve the Playwright submodules used during bun build --compile
• add a regression test that asserts the required chromium-bidi entrypoints are resolvable in the opencode package
• verify the fix by running the targeted test and rebuilding the macOS arm64 CLI binary successfully

Validation

• bun test test/build/chromium-bidi.test.ts
• bun run --cwd packages/opencode script/build.ts --single