Improve WebView retry and offline handling

[cristhianescobar]

Summary

• move offline and page-load recovery into the shared Android WebView wrapper used by record store, marketplace, and studio
• add a dedicated branded WebView error screen with retry support while keeping the shared generic error component reusable
• tighten internal URL detection to allow only http/https NEWM hosts and add regression coverage for lookalike and custom-scheme links
• remove presenter-side one-shot connectivity gating and fix studio page-load analytics to log the correct screen

Validation

• ./gradlew spotlessApply
• ./gradlew :core-ui:desktopTest
• ./gradlew :android:app-newm:assembleDevelopmentDebug

Notes

• no blocking review findings remain after isolating the richer retry UI from the shared ErrorScreen
• remaining risk is low and mostly around optional follow-up UX, like surfacing a message when an external intent cannot be opened