[State Sync Redesign 3.10] Update Sentry state capture chain

The Sentry error reporting chain reads state.metamask at multiple points. Must be updated before the slice is removed, or production error visibility is lost.

Current chain:

ui/index.js: getSentryAppState → maskObject(store.getState(), SENTRY_UI_STATE)
app/scripts/constants/sentry-state.ts: SENTRY_UI_STATE = { metamask: flattenedBackgroundStateMask }
app/scripts/lib/setupSentry.js: getMetaMetricsEnabledFromAppState → appState.state.metamask.participateInMetaMetrics
app/scripts/lib/setup-initial-state-hooks.js: wires getSentryState pre- and post-init

Steps

1. Update getSentryAppState in ui/index.js to build state from ControllerStateManager snapshots + Redux (non-metamask slices)
2. Update SENTRY_UI_STATE mask in sentry-state.ts to use controller-keyed shape (aligning with the background's SENTRY_BACKGROUND_STATE which is already controller-keyed)
3. Update getMetaMetricsEnabledFromAppState in setupSentry.js to read from controller-keyed path (MetaMetricsController.participateInMetaMetrics)
4. Update setup-initial-state-hooks.js wiring
5. Validate: trigger a Sentry error in dev, confirm the masked state payload is correct

Files

• ui/index.js
• app/scripts/constants/sentry-state.ts
• app/scripts/lib/setupSentry.js
• app/scripts/lib/setup-initial-state-hooks.js

Risk

High — if Sentry breaks, we lose production error visibility. Must be validated before and after slice removal.

Dependencies

Issue 3.9 (dual-write removed, but Sentry update can start during dual-write phase)

Context

Part of [State Sync Redesign — Epic 3: UI-controller subscriptions].

Start with getSentryAppState in ui/index.js, then compare sentry-state.ts with the controller-keyed SENTRY_BACKGROUND_STATE. Trace the MetaMetrics lookup in setupSentry.js and the wiring in setup-initial-state-hooks.js. Done means the four files use controller-keyed state and a dev Sentry error shows the correct masked payload before and after slice removal.