davidasix/mobile-layout

[DavidASix]

This PR ended up being huge, and is mostly boilerplate / initial architecture choices.

This moves the mobile app onto Expo Router and adds the first-launch onboarding flow. It also wires app locking into the encrypted local database so secure and no-lock modes both open the app correctly.

• add the tab and stack route structure for clients, tools, calendar, statistics, settings, and client screens
• add paged welcome, feature, and lock-selection onboarding with persisted completion
• store the database key in SecureStore and support biometric/PIN or no-lock preferences
• switch local storage to SQLCipher-enabled op-sqlite with deferred initialization and migrations
• update Expo/EAS config, mobile dependencies, tests, conventions, and mobile app docs

[DavidASix]

Checks pass locally, failing here as I have not committed the migrations directory.