fix(mobile): connecting an environment no longer crashes the header#22521

Connecting a new environment can crash development builds with “Couldn't find a navigation context” when the header checkmark becomes a loading indicator. The toolbar options comparison follows the React element's development-only owner into React Navigation's context.

Compare React elements by type, key, and props, and preserve React component/context objects by identity. This keeps equivalent toolbar updates stable without traversing React internals. It also covers custom content in sheet headers.

Verification: 14 focused toolbar and pairing tests pass. The new regression test exercises a custom toolbar element beneath a context with a throwing default, including equivalent renders and changed content. On the iPhone Duo simulator, auto-connect reaches normal connection-error handling without the navigation render error. No visual styling changes.

Implemented by Claude Opus 5.5 through the T3 Code Claude harness; reviewed and verified by GPT-6.1 through the Codex harness.