fix(sessions): navigate home after leaving session

[RonenMars]

Summary

• Navigate home after Kill it, Leave it, or Kill on idle for new and resumed sessions.
• Suppress the expected session-detail 404 after killing a session.
• Keep error-sheet controls accessible to VoiceOver and XCTest.
• Add a six-case real-streamer Maestro regression matrix.
• Document an Android-first CI design using the streamer's deterministic Docker backend and provider stub.

Test plan

• npm run lint
• npm run typecheck
• npm run test:ci
• npm run test:scripts
• node e2e/run-leave-nav.js
• git diff --cached --check for the documentation addition