# 12. Implement iOS feed fetcher service

meta:
  id: native-business-logic-migration-12
  feature: native-business-logic-migration
  priority: P0
  depends_on: [native-business-logic-migration-09]
  tags: [implementation, ios, networking]

objective:
- Implement feed fetching service with URLSession

deliverables:
- FeedFetcher.swift
- HTTPAuthCredentials.swift
- FetchResult.swift
- NetworkError.swift
- Feed caching implementation

tests:
- Unit: Test URL session configuration
- Unit: Test HTTP auth handling
- Unit: Test error cases (timeout, 404, etc.)
- Integration: Test fetching real feeds

acceptance_criteria:
- Feeds fetch with proper timeout (15s)
- HTTP auth supported
- Error handling complete
- Response caching implemented
- Performance: <5s for typical feed

validation:
- Run unit tests
- Test with Network Link Conditioner

notes:
- Use URLSession with proper configuration
- Implement exponential backoff for retries
- Respect Cache-Control headers