chore(js-ts): Replace AnyAction with typed RootAction union

[devin-ai-integration]

Summary

Addresses the TODO at app/store/index.ts to improve type safety by replacing AnyAction with real Action types.

Changes

• New file app/store/actionTypes.ts: Defines a RootAction union type that aggregates all known typed action types across the codebase:

  • UserAction, SecurityAction, SdkAction, OnboardingActionTypes, NavigationAction, RpcEventAction, AccountAction, LegalNoticesAction, FiatOrderAction
  • Plus Action<string> as a fallback for the 11 action modules still written in JS (alert, bookmarks, browser, collectibles, infuraAvailability, modals, notification, privacy, settings, transaction, wizard). This fallback can be removed as those files are migrated to TypeScript.

• app/store/index.ts: persistReducer now uses RootAction instead of AnyAction. Removed the TODO comment.

• app/core/redux/types.ts: ReduxStore type now uses RootAction instead of AnyAction. Removed the TODO comment.

• app/reducers/index.ts: rootReducer is explicitly typed as Reducer<RootState, RootAction> (cast from the internal combineReducers which still uses any due to narrow per-reducer action types). Updated comment to explain the approach.

• app/components/hooks/useThunkDispatch.ts: ThunkAction and useThunkDispatch now use RootAction instead of AnyAction.

• app/core/DeeplinkManager/DeeplinkManager.ts: dispatch property and constructor param now use RootAction and RootState instead of AnyAction/any. Removed two TODO comments.

After this change, zero references to AnyAction remain in the app/ directory.

Review & Testing Checklist for Human

• Verify RootAction union in app/store/actionTypes.ts covers all typed action modules — check no typed action union was missed
• Confirm the Action<string> fallback doesn't mask type errors for already-typed dispatch call sites
• Run tsc --noEmit to verify no type regressions

Notes

• The combineReducers call still uses any internally because individual typed reducers (e.g. userReducer accepting UserAction) have narrow action types that are not assignable to the wider RootAction union under strict function parameter contravariance. The cast to Reducer<RootState, RootAction> at the export boundary is safe because all reducers handle unknown action types via their default case.
• As the remaining 11 JS action files are migrated to TypeScript (tracked in the JS→TS migration playbooks), their action types should be added to RootAction and the Action<string> fallback can be removed.

Link to Devin session: https://app.devin.ai/sessions/5b5e0a3b9818479cbfa874c5d5da1361
Requested by: @dr-phil

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✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

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