[Due for payment 2026-08-05] feat: resolve Search loading gates from snapshot terminal state

[mountiny]

Problem

The Search page decides whether to show its loading skeleton from the shape of snapshot data (data === undefined) and a stored search.isLoading flag. Both can lie: a successful response that writes no snapshot data leaves data undefined forever, and a reload or dropped response can strand isLoading, so the skeleton hangs indefinitely.

Solution

Move Search loading gates onto the snapshot's explicit terminal lifecycle state (loading | loaded | error). Update isSearchDataLoaded, useSearchLoadingState, useSearchPageSetup, and the narrow-layout loading bar to read from state instead of stored flags. Stamp hash on terminal writes so anti-stale matching works on dataless responses. Add isSearchPending() helper and unit tests for the read side.

PR

#96388

Issue Owner

Current Issue Owner: @mallenexpensify