Upgrade OpenTUI to v0.1.70

Improvements

• CoreSupport multi-select questions
• CoreDocument cargofmt in docs@marc2332
• TerminalStop escape key propagation from dialogs
• TerminalUse full file path for fuzzy matching in autocomplete@bagatka
• DesktopRevert fix for opening external links in default browser
• DesktopCache session-scoped stores and add optional context gating
• DesktopIncrementally render turns with markdown caching and lazy diff rendering
• DesktopGate hydration side-effects and handoff while stores load
• DesktopPrefetch adjacent sessions in the app
• DesktopImplement chunked message loading and lazy diff loading for improved performance
• DesktopFix project sidebar folder name display issue@0xajka