Add iOS Unit Test Suite - 91 Tests

[Jing-yilin]

Summary

This PR adds a comprehensive iOS unit test suite covering core functionality across ViewModels, APIClient, models, Keychain, and ImageCache.

Test Coverage

• 91 total unit tests across the iOS codebase
• AlertsViewModel tests
• DiscoverViewModel tests
• APIClient tests
• DTO/Model tests
• KeychainHelper tests
• ImageCache tests
• Mock implementations for testing (MockAPIClient, MockURLProtocol)

Additional Changes

This branch includes several backend improvements and features:

• ScrapingBee integration for Kickstarter crawling
• Campaign backfill endpoint (POST /api/admin/backfill)
• Enhanced campaign model with backers_count field
• Configurable crawl depth via environment variables
• Category and subcategory crawling
• Database schema improvements (p_id → pid migration)
• Enhanced investor metrics and momentum alerts
• CI/CD improvements and security enhancements

Test Plan

• All 91 iOS unit tests pass
• Backend tests passing in CI

🤖 Generated with Claude Code

[Jing-yilin]

Codex Review

[Low] testLoadCategoriesSkipsIfAlreadyLoaded does not observe the code path it is meant to protect

DiscoverViewModel.loadCategories() calls fetchCategories(), but this test snapshots mock.fetchCampaignsCalls.count instead. Because MockAPIClient does not record category fetches, the assertion still passes even if loadCategories() regresses to hitting the categories endpoint on every call. In practice, the suite is not actually covering the "skip refetch when already loaded" behavior this test claims to verify.
Refs: ios/KickWatch/Tests/DiscoverViewModelTests.swift:159, ios/KickWatch/Tests/MockAPIClient.swift:38

Validation

• cd backend && go test ./...
• cd ios && export DEVELOPMENT_TEAM=7Q28CBP3S5 && xcodegen generate
• cd ios && xcodebuild -project KickWatch.xcodeproj -scheme KickWatch -destination 'platform=iOS Simulator,name=iPhone 17' test
• Result: backend suite passed; iOS suite passed with 91 tests on February 28, 2026.

Reviewed by Codex