Unify portal connection and Speed home UX

[burkben]

Summary

• move BLE/demo transport ownership into one application-level controller so connection state and passes persist across tabs, including Race and Live diagnostics
• auto-connect on BLE-capable devices with finite scan windows, capped exponential retry, terminal recovery states, sticky manual disconnect, and scan-free Guided Access prewarming
• make the accessible status pill the connect/retry/confirmed-disconnect control and remove Speed's dedicated connection button
• add the current/last-car Speed hero with catalog identity/photo, nickname and UID fallbacks, and speed context
• surface truthful browser/native persistence degradation while fully wiring in-memory repositories after SQLite absence or initialization failure
• isolate repository initialization/hydration so a failed domain falls back independently without clearing data already loaded by healthy repositories
• classify a strict subset of repository failures as partial degradation and all-domain failure as full memory mode
• add accessibility announcements, roles/states, and app-plus-system reduce-motion handling across touched controls and dynamic states

Compatibility

• legacy control-service and modern MPID discovery/auth/decoding paths remain unchanged
• no SQLite schema or protocol migration
• web and Simulator never construct or scan BLE; static web export uses an explicit no-native SQLite adapter
• Race setup and race engine behavior are unchanged

Validation

• npm test (322 tests)
• npm run typecheck
• Expo static web export across all routes

Closes #31
Closes #32
Closes #33

Related to #28