core: implement app-wide error tracking with Sentry

[EmeditWeb]

Problem

When the app crashes in production there is no
error reporting. Bugs go undetected.

What To Build

1. Install @sentry/react-native
2. Configure Sentry in app entry
3. Error boundaries with Sentry
4. User context on wallet connect
5. Custom breadcrumbs
6. Performance monitoring
7. Source map upload on EAS build

Files To Touch

• app/_layout.tsx
• app.config.ts
• .env.example
• All service files

Acceptance Criteria

• Unhandled errors reported to Sentry
• User context attached to errors
• Source maps uploaded on production build
• No sensitive data in error reports
• npx expo export --platform web passes

Mandatory Checks Before PR

• npx expo export --platform web passes
• Sentry DSN in .env.example not .env
• PR references this issue

[Francis6-git]

I will set up Sentry for production error reporting by configuring the SDK, adding error boundaries, attaching user context on wallet connection, and implementing custom breadcrumbs throughout the application.

ETA 12 hours.

[grantfox-oss]

🦊 GrantFox — @Francis6-git has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #20)
2. Your PR will be reviewed by the StepFi-app maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Francis6-git's PR #30 was approved and merged by @EmeditWeb.

🏆 @Francis6-git: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (188 total points). Track your full progress on GrantFox.

👏 Great work, @Francis6-git! Keep contributing to StepFi-app.