[zelentsov-dev]

Summary

• Update pinned Apple OpenAPI specification from 4.5.1 (1,001 paths, 1,303 operations) to 4.6 (1,027 paths, 1,337 operations, SHA-256: 74732362a91236dcb66eb1620f8be18c2b6060771269b483eab578473bb32763).
• Add RetentionMessagingModels.swift and 23 new SubscriptionsWorker tools covering retention messages, versions, localizations (with 66/144 char limits, emoji guard, and App Review price/discount lint guard), retention offers (with inline retentionOfferPrices and waitBetweenOffersMonths validation), and subscription retention relationships (get_retention_message_for_subscription, set_retention_message, add_retention_message_offers, remove_retention_message_offers).
• Extend AssetsWorker for target_type = "retentionMessageVersion" (feature = "RETENTION_MESSAGING", to-one /v1/retentionMessageVersions/{id}/placement read, app ownership verification via GET /v1/apps/{appId}/retentionMessages?filter[id]=..., editable state check, and rejection of video and reorder_placements).
• Extend ReviewSubmissionsWorker (review_submissions_add_item, review_submissions_list_items, review_submissions_get, review_submissions_list) with retention_message_version_id / retentionMessageVersions support.
• Update manifest.json, tools/*.json, ASCOpenAPICoverage.swift, ASCCoverageInventory.swift, ASC-OPENAPI-COVERAGE-GENERATED.md, documentation, and contract tests (RetentionMessagingContractTests.swift).

Verification

• swift test (1989 tests in 153 suites passed)
• swift build -c release (0 warnings)
• .build/release/asc-mcp openapi-contract-check --spec Tests/ASCMCPTests/Fixtures/OpenAPI/app-store-connect-4.6.oas.json --strict
• python3 -B .github/workflows/scripts/assets_mcp_smoke.py --binary .build/release/asc-mcp --expected-version 4.2.0
• python3 .github/workflows/scripts/apple_spec_drift.py