feat: [FE] Add favorites section to homepage

[Mbeaulne]

Description

Allow users to favorite pipelines and runs. Favorited items appear in a dedicated section on the homepage below "Recently Opened."

Implementation details

• Star/favorite toggle on:
  • Pipeline rows in the Pipelines tab
  • Run rows in the Runs tab
  • Pipeline editor toolbar
  • Run detail toolbar
• Store favorites in localStorage keyed by item type + ID (similar to existing FavoriteComponentToggle)
• Homepage section shows favorited items as a horizontal list or compact card row
• Each card shows: star icon, item name, type badge, status (for runs)
• Click navigates to the item
• Unfavorite directly from the homepage section via star toggle
• Empty state: "No favorites yet. Star a pipeline or run to pin it here."

Reusable existing code

• src/components/shared/FavoriteComponentToggle.tsx — star toggle pattern (currently only for components)

Relevant files to modify

• src/routes/Home/Home.tsx — add section
• New hook: useFavorites.ts — localStorage CRUD for favorites
• src/components/Home/PipelineSection/PipelineRow.tsx — add star toggle
• src/components/Home/RunSection/RunRow.tsx — add star toggle