feat(integrations): Stage 8A - integration abstractions contracts
- Add ApiException base class (statusCode, message, body)
- Add ApiClient abstract class (initialize, dispose, isReady, execute<T>)
- Add RetryPolicy abstraction (NoRetryPolicy, ExponentialBackoffRetryPolicy)
- Add RateLimiter abstraction (NoRateLimiter, TokenBucketRateLimiter)
- Add IntegrationHealthCheck contract (HealthCheckResult value object)
- Add WebhookHandler contract (WebhookEvent, WebhookResult, WebhookProcessingStatus)
- Add ChannelAdapter contract (ChannelProduct, ChannelOrder, ChannelOrderItem, ChannelInventoryCount)
- Replace Calculator placeholder with barrel exports for all 7 contract files
- Refactor WooCommerceApiClient to implement ApiClient contract
- Refactor WooCommerceApiException to extend ApiException
- Add integrations dependency to feature_wordpress pubspec
- Add packages/integrations to TESTABLE and ANALYZABLE in run_all_tests.sh
- Add 38 tests for all contracts and value objects
- dart analyze clean (no issues in integrations and feature_wordpress)
- Tests: 38/38 integrations, 319/319 feature_wordpress
Mike Kell
ec66626074