feat: isolate Angular runtime per render

[Lojhan]

Summary

• replace shared TestBed fixture management with isolated Angular runtime applications for render and renderHook
• scope cleanup and fireEvent flushing to the current Poku DOM scope, and add Angular 18/19 zoneless compatibility handling
• expand Angular lifecycle, cleanup, hook, and scope-isolation coverage and add a publish smoke check script

Validation

• npm test
• npm run typecheck
• npm run check:publish

Notes

• the publish smoke script was added because package.json referenced tools/publish-smoke.mjs but the file was missing
• workspace-local file dependency links were removed from the Angular package metadata so the standalone repo stays CI-safe