perf(utils): ignore stale useFetch responses

[JustYannicc]

What changed

• Add a latest-run guard to useFetch so older in-flight window.electron.httpRequest responses cannot update data, errors, loading state, or callbacks after a newer request starts.
• Invalidate active runs when execute flips false or the hook unmounts.
• Refetch function-valued URLs when their resolved initial request URL changes, while skipping duplicate internal rerenders for the same resolved URL/options.
• Add a focused hook harness covering stale revalidate responses and function URL request-input changes.

Why

Rapid revalidate, pagination, or request-input changes can leave multiple HTTP requests in flight. Before this patch, an older response could resolve after a newer run and overwrite newer data or invoke stale callbacks.

Compatibility impact

• useFetch return shape and option names are unchanged.
• No abort signal is added to the Electron HTTP request path; stale responses are ignored when they settle.
• Function URL behavior remains conservative: a fresh function identity does not refetch by itself if it resolves to the same initial request URL with the same request options.

How tested

• Before evidence: node --test scripts/test-use-fetch-stale-runs.mjs failed before the hook change because stale data overwrote the latest result, and a changed function URL request input did not start a second request.
• After evidence: node --test scripts/test-use-fetch-stale-runs.mjs passes on this PR branch.
• Stack validation from the integration branch: node --test scripts/test-use-fetch-stale-runs.mjs scripts/test-abortable-promise-hooks.mjs scripts/test-menubar-storage-remounts.mjs scripts/test-raycast-cache-size-index.mjs passed 20 tests.
• Clean PR branch note: the nearby stack test scripts are not present on current origin/main yet, so the focused useFetch test was rerun here.
• LSP diagnostics: no TypeScript errors reported for src/renderer/src/raycast-api/hooks/use-fetch.ts.

Stack validation

Draft until the consolidation stack lands. This targets upstream main and depends on #530, #531, #532, #533, #534, and #535.

[JustYannicc]

Superseded by consolidated upstream PR #555.