test(screens): add comprehensive SubmitProofScreen test coverage (#81)

[Abdul-dev-creator]

Overview

This PR adds a comprehensive test suite for src/screens/SubmitProofScreen.tsx — the most complex screen in the app, which previously had zero test coverage. The suite locks in the core value loop (task → proof → reward): camera permission handling, photo capture and preview, proof submission with activity creation and stat updates, offline queueing, retake reset, empty state, and location display/errors.

Related Issue

Closes #81

Changes

🧪 SubmitProofScreen Test Suite (18 test cases)

• [ADD] src/__tests__/SubmitProofScreen.test.tsx
• Covers the full camera capture flow: permission prompt → grant → capture → preview.
• Verifies successful submission creates a pending activity, updates user stats (treesPlanted, co2Reduced), starts proof-status polling with the correct activity context, and defers the notification until polling confirms.
• Verifies submission without a proofId confirms the activity immediately and fires the reward local notification with deep link payload.
• Covers offline/failed submission: activity queued as pending with error surfaced in the UI.
• Covers retake flow: preview cleared, state reset back to capture mode.
• Covers empty state when no taskId is provided in route params.
• Covers location loading placeholder and location error display.
• Covers progress labels (Uploading..., Verifying..., failed, confirmed) and disabled button states while submitting.
• Covers capture failure alerting and header back navigation.

🔧 Mocking Infrastructure

• [ADD] Mocks for react-native-vision-camera (useCameraPermission, useCameraDevice, Camera.takePhoto), @react-navigation/native, useLocation, useProofSubmit, useProofStatus, and scheduleLocalNotification.
• Uses deferred mock references inside jest.mock factories so hoisted factories never capture uninitialized bindings.

Screenshots / Verification

npm run lint ✅ completed (existing repo warnings only)
npm run typecheck ✅ passed
npx tsc --noEmit ✅ passed
npm test ✅ passed (34 suites / 303 tests, incl. 18 new SubmitProofScreen tests)

[cybermax4200]

The ci checks are failing please fix them