feat(refs): react-native-engineer — testing + error-handling (Level 2→3)

[notque]

Summary

• Adds testing.md and error-handling.md to react-native-engineer/references/
• Updates agent loading table with two new signal rows
• Updates Error Handling section with routing hints for the new files
• Level moves from 2 (Domain) → 3 (Deep): both new files include grep/rg detection commands

Targets Processed

Agent	Before	After	New Files
react-native-engineer	Level 2	Level 3	2

New Reference Files

testing.md (271 lines):

• RNTL 12+ patterns: getByRole, waitFor, userEvent
• jest-expo config for native module mocking via moduleNameMapper
• AsyncStorage mock setup in jest.setup.ts
• Anti-patterns: getByTestId, snapshot tests, per-file navigation mocks
• Detection commands for all anti-patterns
• Error-fix mappings for common jest/RNTL errors
• Version notes: RNTL 12.0/12.4, Expo SDK 50, RN 0.73 New Architecture

error-handling.md (332 lines):

• ErrorBoundary setup at screen and navigation root level
• Sentry init sequence (must run before registerRootComponent)
• Typed fetch error handling (network vs HTTP vs JSON parse errors)
• Global unhandled promise rejection capture for Hermes
• Anti-patterns: empty catch, console.error-only reporting, missing boundaries, unsafe API response access
• Detection commands for all anti-patterns
• Error-fix mappings for 6 common production crash patterns
• Version notes: @sentry/react-native 5.0, React 18 startTransition, RN 0.71/0.73

Validation Gate

All three domain-specific test queries correctly resolved to the new references via loading table signal matching. Both files KEEP.

Test Plan

• python3 scripts/audit-reference-depth.py --agent react-native-engineer --verbose shows Level 3
• python3 scripts/validate-references.py --agent react-native-engineer passes structural checks
• CI lint passes (no Python files modified)