Move actions/checkout, setup-node, cache, and upload-artifact to their current majors (Node 24 runtime). Run the browser suite as a sharded matrix aggregated by an e2e-gate job, so the required status check stays a stable name as the shard count scales. Vitest runs once (shard 1). Ready for the incoming e2e test expansion.
Extract the shared PHP/Composer/Node/database/Passport setup into a composite action, and run the backend suite (Unit + Feature) and the frontend/e2e suite (Vitest + Playwright browser tests) as two parallel jobs. This isolates the flaky browser suite so it can be rerun on its own, surfaces failures by area, gives the growing e2e suite room to shard, and uploads Playwright artifacts on failure.
