Update the existing migration work to the current Solid 2 beta surface and remove the remaining deprecated compatibility APIs so the next action/submission redesign can start from a stable checkpoint.

Made-with: Cursor

Align the router with Solid 2 beta primitives by refactoring actions around Solid's action model, removing deprecated async APIs, and documenting the new submission and optimistic update patterns.

Made-with: Cursor

Document the Solid 2 beta branch for release tooling and add Solid-style Cursor rules tailored to this router repo so future work follows the current architecture, testing, and changeset expectations.

Made-with: Cursor

Record the changesets prerelease state for the Solid 2 migration branch so future versioning runs produce next-tagged prerelease versions.

Made-with: Cursor

Keep route outlet consumption inside JSX tracking and avoid reading the router source signal directly during setup so Solid 2 no longer warns on router construction.

Made-with: Cursor

Record the follow-up patch release note for the client navigation rendering regression and Solid 2 router setup warning fix.

Made-with: Cursor