ci: Add iOS Integration Style Unit Tests

[BrandonStalnaker]

Summary

• iOS New Architecture: logCommerceEvent now maps productActionType through [RCTConvert MPCommerceEventAction:] (same as the legacy bridge) instead of casting to MPCommerceEventAction, fixing scrambled product commerce actions.
• Promotions: promotionActionType is mapped with [RCTConvert MPPromotionAction:] because JS order (View=0, Click=1) does not match MPPromotionAction (Click=0, View=1). Applied in New Arch logCommerceEvent and in [RCTConvert MPPromotionContainer:].
• Legacy helper: RCTConvert (MParticle) MPCommerceEvent: now uses MPCommerceEventAction: for productActionType instead of a raw cast.CI / tests: PR workflow runs focused XCTests in the sample app (RCTConvertCommerceMappingTests) covering enum mapping and JSON → MPCommerceEvent / MPPromotionContainer. Sample README documents how to run them locally.

Testing Plan

• Automated: xcodebuild test in CI (sample workspace) with -only-testing:MParticleSampleTests/RCTConvertCommerceMappingTests after pod install.
• Manual (recommended once): On an iOS New Arch build, log a product-action commerce event and a promotion commerce event and confirm actions match JS constants in verbose / payload output.
• Note: XCTests exercise RCTConvert and the JSON MPCommerceEvent assembly path; they do not drive the TurboModule JSI struct entry point directly.

Master Issue

Closes https://go.mparticle.com/work/REPLACEME

[cursor]

PR Summary

Low Risk
Changes are limited to sample tests, CI, and docs; no production SDK or app runtime code in this diff.

Overview
Adds RCTConvertCommerceMappingTests to the sample iOS test target to lock in JS ProductActionType / PromotionActionType integers → Apple SDK enums and JSON → +[RCTConvert MPCommerceEvent:] (including promotion container wiring). The tests intentionally cover the legacy RCTConvert assembly path, not the TurboModule codegen entry point.

The iOS Sample App PR workflow step switches from xcodebuild build-only to test scoped to that suite (-only-testing:MParticleSampleTests/RCTConvertCommerceMappingTests), with a comment reminding maintainers to keep the job display name aligned with branch protection. sample/README.md documents how to run the same tests locally.

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