Migrate app to Expo SDK 55

[devin-ai-integration]

Summary

• Upgrades the Expo app to Expo SDK 55, React Native 0.83.6, React 19.2.0, and matching Expo/RN package versions.
• Regenerates native Android/iOS project files for the SDK 55 templates, including the new Expo React host setup, Gradle wrapper/build updates, and refreshed Podfile/Podfile.lock.
• Updates app code for SDK 55 compatibility by using the new expo-file-system File/Paths API and replacing the removed Ionicons md-arrow-up glyph.

Review & Testing Checklist for Human

• Build and launch the iOS app locally with Xcode or EAS to verify the regenerated native iOS project and Podfile.lock on macOS.
• Smoke-test image download/save and chat message sending, since those touched SDK/API compatibility paths.
• Confirm Android debug builds and launches on an emulator/device.

Notes

Verified locally:

• cd app && pnpm exec tsc --noEmit
• cd app && pnpm exec expo export --platform web --output-dir ./dist-web
• cd app/android && ANDROID_HOME=/usr/lib/android-sdk ANDROID_SDK_ROOT=/usr/lib/android-sdk ./gradlew :app:assembleDebug
• cd app/ios && pod install --repo-update for Podfile.lock regeneration

expo-doctor reports 17/18 checks passing; the remaining warning is Expo's expected non-CNG/native-folder warning about app config fields when android/ and ios/ are checked in.

Link to Devin session: https://app.devin.ai/sessions/bd1a3dd8022f4320a539bc5fe8d4aef0
Requested by: @dabit3

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[devin-ai-integration]

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[devin-ai-integration]

✅ Devin Review: No Issues Found

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

View in Devin Review to see 5 additional findings.