unstable_data → data (for use with Single Fetch)
unstable_flushSync → flushSync (useSubmit, fetcher.load, fetcher.submit)
unstable_viewTransition → viewTransition (<Link>, <Form>, useNavigate, useSubmit)
~~future.unstable_optimizeDeps → future.v3_optimizeDeps (Docs)~~
- ⚠️ This flag was not intended to stabilize in Remix v2 and was reverted back to future.unstable_optimizeDeps in 2.13.1
future.unstable_lazyRouteDiscovery → future.v3_lazyRouteDiscovery (Docs)
future.unstable_singleFetch → future.v3_singleFetch (Docs)

Stabilize React Router APIs in Remix (#9980)
- Adopt stabilized React Router APIs internally
  - Single Fetch: unstable_dataStrategy -> dataStrategy
  - Lazy Route Discovery: unstable_patchRoutesOnNavigation -> patchRoutesOnNavigation
- Stabilize public-facing APIs
  - Single Fetch: unstable_data() -> data()
  - unstable_viewTransition -> viewTransition (Link, Form, navigate, submit)
  - unstable_flushSync> -> <Link viewTransition> (Link, Form, navigate, submit, useFetcher)
Stabilize future flags (#10072, #10092)
- future.unstable_lazyRouteDiscovery -> future.v3_lazyRouteDiscovery
- future.unstable_optimizeDeps -> future.v3_optimizeDeps
- future.unstable_singleFetch -> future.v3_singleFetch

@remix-run/dev - Stop passing request.signal as the renderToReadableStream signal to abort server rendering for cloudflare/deno runtimes because by the time that request is aborted, aborting the rendering is useless because there's no way for React to flush down the unresolved boundaries (#10047)
- This has been incorrect for some time, but only recently exposed due to a bug in how we were aborting requests when running via remix vite:dev because we were incorrectly aborting requests after successful renders - which was causing us to abort a completed React render, and try to close an already closed ReadableStream
- This has likely not shown up in any production scenarios because cloudflare/deno production runtimes are (correctly) not aborting the request.signal on successful renders
- The built-in entry.server files no longer pass a signal to renderToReadableStream because adding a timeout-based abort signal to the default behavior would constitute a breaking change
- Users can configure this abort behavior via their own entry.server via remix reveal entry.server, and the template entry.server files have been updated with an example approach for newly created Remix apps
@remix-run/express - Fix adapter logic for aborting request.signal so we don't incorrectly abort on the close event for successful requests (#10046)
@remix-run/react - Fix bug with clientLoader.hydrate in a layout route when hydrating with bubbled errors (#10063)