#7442 Fix local client state across sibling components

Fixes #7426, where calling a local client-state setter from a sibling component could raise a ReferenceError and leave the displayed value unchanged.

The compiler now detects when local client state is shared across components and keeps those components in a compatible React scope. Added a compiler regression test and a Playwright test that verifies the sibling setter updates the rendered value. Included changelog entries for both affected packages.

Testing: Targeted unit and Playwright tests, Ruff, Pyright, and git diff --check pass locally.