fix(angular-rspack): handler accumulation and watchOptions for double rebuilds

[faileon]

Current Behavior

1. Handler accumulation: The compilation, beforeCompile, and done hooks are registered inside watchRun, causing new handlers to be added on every rebuild cycle. This leads to performance degradation and duplicate operations during watch mode.
2. Double rebuilds: Rapid filesystem events (e.g., editor backup/swap files) trigger multiple rebuilds because there's no aggregation timeout configured.
3. No watchOptions configuration: Users cannot customize watcher behavior (aggregateTimeout, ignored patterns, etc.).

Expected Behavior

1. Hooks should be registered once outside of watchRun to prevent accumulation. Shared state is used to pass data between watch cycles and compilation hooks.
2. A default aggregateTimeout: 50 batches rapid filesystem events to prevent double rebuilds.
3. Users can provide custom watchOptions to configure watcher behavior, with user options taking precedence over defaults.

Related Issue(s)

#34142 (comment)

[netlify]

👷 Deploy request for nx-docs pending review.

Visit the deploys page to approve it

Name	Link
🔨 Latest commit	18d727b

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Review	Updated (UTC)
nx-dev	Ready	Preview	Jan 20, 2026 11:20am

[nx-cloud]

View your CI Pipeline Execution ↗ for commit 18d727b

Command	Status	Duration	Result
nx affected --targets=lint,test,test-kt,build,e...	✅ Succeeded	3m 32s	View ↗
nx run-many -t check-imports check-lock-files c...	✅ Succeeded	2m 30s	View ↗
nx-cloud record -- nx-cloud conformance:check	✅ Succeeded	11s	View ↗
nx-cloud record -- nx format:check	✅ Succeeded	2s	View ↗
nx-cloud record -- nx sync:check	✅ Succeeded	<1s	View ↗

---

☁️ Nx Cloud last updated this comment at 2026-01-20 13:24:49 UTC

[github-actions]

This pull request has already been merged/closed. If you experience issues related to these changes, please open a new issue referencing this pull request.