fix(mobile): sidebar no longer re-registers shortcuts every render#22135

On mobile, every ThreadNavigationSidebar render rebuilt the thread list, handed LegendList a new data array, and re-registered the 9 thread jump shortcuts. Each re-registration re-rendered the app-root keyboard provider and sent native a new command list. After the React Compiler migration #21145, the list derivations stayed mutable across later hook calls, so the compiler silently dropped the cache holding listItems.

The fix restructures the sidebar so the compiler can cache it, and removes the four useMemos it still had:

• Every hook in the pane now runs before the list derivations. A small useSidebarListFilters hook owns the filter state and project scopes, so the pane gets them as frozen hook results.
• useThreadJumpShortcuts registers once on mount and reads the latest list through useEffectEvent, so it no longer depends on the list at all. HomeScreen uses the same hook and benefits too. The shortcuts now keep the priority they got at mount instead of jumping to the top on each render; only HomeScreen and the sidebar register them, and they're never on screen together.

Proof:

• New test caches the sidebar thread list in apps/mobile/src/reactCompilerCoverage.test.ts checks that buildThreadListV2ListItems runs only on the cache-miss branch. It fails with main's sidebar and passes here.
• New test threadKeyboardShortcuts.test.tsx checks that the hook registers once across re-renders and still jumps within the latest list. It fails on main's hook.
• In a jsdom harness running the compiled sidebar, 20 unrelated renders caused 20 shortcut re-registrations, keyboard provider renders and LegendList data changes on main, and none here.
• Ran vp test run on reactCompilerCoverage.test.ts (896 passed) and both keyboard tests, plus mobile typecheck.
• Not checked: a real device or simulator. There is no visible UI change, so no screenshots.

Claude Opus 5.5 via Claude Code in T3 Code