feat favorites infrastructure

[Mbeaulne]

Description

Added a new useFavorites React hook that provides functionality for managing user favorites in localStorage. The hook supports adding, removing, and toggling favorite items (pipelines and runs), with automatic synchronization across browser tabs using useSyncExternalStore. Includes comprehensive test coverage with 124 test cases covering all functionality including duplicate prevention, cross-tab synchronization, and type-specific item handling.

Related Issue and Pull requests

Type of Change

• Bug fix
• New feature
• Improvement
• Cleanup/Refactor
• Breaking change
• Documentation update

Checklist

• I have tested this does not break current pipelines / runs functionality
• I have tested the changes on staging

Screenshots (if applicable)

Test Instructions

1. Import and use the useFavorites hook in a React component
2. Test adding favorites using addFavorite(item)
3. Test removing favorites using removeFavorite(type, id)
4. Test toggling favorites using toggleFavorite(item)
5. Verify isFavorite(type, id) correctly identifies favorite status
6. Open multiple browser tabs to verify cross-tab synchronization works
7. Run the test suite to ensure all functionality passes

Additional Comments

The hook uses typed storage for persistence and implements caching to ensure stable references for useSyncExternalStore. It properly handles different item types (pipeline/run) with the same ID as separate entities.

[github-actions]

🎩 To tophat this PR:

You can add the following URL parameter to your browser to tophat this PR:

`?tophat_location=03-23-feat_favorites_infrastructure/ce9e2da`

---

[Mbeaulne]

• remove old home page #2056
• Default dashboard flag #2055
• Add components section #2025
• Add dashboard home view with favorites, recently viewed, and my runs sections #2011
• moves app footer #2010
• add new section to the side bar #2004
• Updates runs and pipelines designs #2003
• Adds runs and filters #2002
• update favourite and recent cards #2001
• Updates revently viewed #2000
• Adds recently viewed #1999
• Update design for favourites #1998
• add favourites to new dashboard #1997
• feat dashboard layout #1996
• Feat recently viewed #1986
• feat_favorites_filter #1985
• feat_favorites_homepage_section #1983
• feat_favorites_toggle_ui #1982
• feat favorites infrastructure #1980 👈 (View in Graphite)
• Dashboard and beta #1932
• Add Claude AI skills for project conventions and development standards #1931
• master

This stack of pull requests is managed by Graphite. Learn more about stacking.

[Mbeaulne]

Reviewer note: Clean, stable PR. useFavorites.ts and its tests are the real foundation of the favorites feature and remain unchanged throughout the rest of the stack. Safe to review in isolation.

[camielvs]

LGTM

[camielvs]

Some things are being caught by knip. Presumably they will be consumed later in the stack. For completeness (and if we ever need to roll back) it may be worth adding the file to knip.json -> ignore and then removing as appropriate.

[Mbeaulne]

Merge activity

• Apr 10, 8:38 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Apr 10, 8:42 PM UTC: Graphite rebased this pull request as part of a merge.
• Apr 10, 8:45 PM UTC: @Mbeaulne merged this pull request with Graphite.