Stabilize project grouping settings selector

[cursor]

What Changed

• Added a shared selectProjectGroupingSettings selector in logicalProject.ts.
• Replaced repeated inline project-grouping settings selectors in Sidebar, ChatView, root event routing, and new-thread creation with the stable selector.
• Added React Scan before/after recordings under artifacts/react-performance/:
  • before-react-scan-project-grouping.webm
  • after-react-scan-project-grouping.webm

Why

Inline object selectors were creating a new selector function on every render. When large parents like Sidebar or ChatView re-rendered for unrelated state, useSettings recomputed a fresh project grouping object, invalidating downstream memoized project grouping/environment derivations and increasing rerender work. A module-level selector keeps the selector identity stable and lets unrelated parent renders reuse the same selected grouping object.

React Doctor was run for a full scan and a diff scan. The remaining diff findings are pre-existing large-component/effect/loop diagnostics in Sidebar/ChatView; the new helper and new-thread call site have no React Doctor diagnostics.

UI Changes

No intentional UI behavior change. React Scan recordings with the same authenticated navigation flow are committed in artifacts/react-performance/:

• Before: artifacts/react-performance/before-react-scan-project-grouping.webm
• After: artifacts/react-performance/after-react-scan-project-grouping.webm

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

Validation:

• bun fmt
• bun lint (passes with existing warnings)
• bun typecheck
• npx -y react-doctor@latest . --json --offline --fail-on none
• npx -y react-doctor@latest . --diff main --json --offline --fail-on none

  

Note

Stabilize project grouping settings selector to prevent unnecessary re-renders

Extracts a shared selectProjectGroupingSettings selector function in logicalProject.ts and replaces inline object selectors in ChatView, Sidebar, useHandleNewThread, and EventRouter. Inline selectors construct a new object on every render, causing unnecessary re-renders in components that use useSettings; a stable shared selector avoids this.

^{Macroscope summarized bfc6cd8.}