feat(privacy): add the refundHandling data processing purpose

[devin-ai-integration]

Description

Adds PLYDataProcessingPurpose.refundHandling (MOB-581), mirroring Purchasely-iOS-Sources#804. Dart → bridge token is REFUND_HANDLING (same SCREAMING_SNAKE convention as the others); the native SDK emits "refund-handling" in X-PRIVACY-CONSENT-REVOKED-FEATURES. Not part of allNonEssentials, no behaviour beyond carrying the flag. Android bridge untouched — its when drops the unknown token.

Also fixes a pre-existing iOS bridge bug: ALL_NON_ESSENTIALS short-circuited to [.allNonEssentials] and silently dropped any other purpose passed alongside (e.g. identifiedAnalytics, now refundHandling). The switch is now a plain compactMap including ALL_NON_ESSENTIALS; the native manager unions the façades.

-let purposes = if purposesArg.contains("ALL_NON_ESSENTIALS") { Set([.allNonEssentials]) } else { Set(purposesArg.compactMap { ... }) }
+let purposes = Set(purposesArg.compactMap {
+    case "ALL_NON_ESSENTIALS": .allNonEssentials
+    ...
+    case "REFUND_HANDLING": .refundHandling

Dartdoc on revokeDataProcessingConsent documents the replace-set semantics (call replaces the stored set, [] grants everything back, allNonEssentials excludes identifiedAnalytics/refundHandling).

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📦 SDK Version Update (updating native SDK dependencies)
• 📚 Documentation update
• 🔧 Configuration/CI change

Testing

• iOS example app builds successfully (flutter build ios --simulator) — see notes
• Android example app builds successfully (flutter build apk) — not touched
• Unit tests pass (flutter test), plus flutter analyze and dart format --set-exit-if-changed .
• Manually tested on iOS simulator/device
• Manually tested on Android emulator/device

Local iOS verification against the Sources repo (PR #804 branch, i.e. develop + refundHandling): the full SwiftPM flutter build ios --simulator run resolved the local Purchasely package but aborted before compiling because this machine has no iOS 26.5 simulator runtime installed. As a substitute, the bridge's revokeDataProcessingConsent mapping (including case "REFUND_HANDLING": .refundHandling) was compiled in a scratch SwiftPM package importing the local Purchasely product (Mac Catalyst destination): ** BUILD SUCCEEDED **. So the Swift change compiles against the 6.2.0 API; the full plugin build will be exercised by CI once the pin is bumped.

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my own code
• I have commented my code where necessary
• I have updated the documentation accordingly
• My changes generate no new warnings
• All CI checks pass

Related Issues

MOB-581

Additional Notes

Draft until Purchasely iOS 6.2.0 ships. .refundHandling does not exist in the pinned 6.1.0, so ios-unit-tests, build-ios and build-ios-swiftpm are expected to fail on this PR. Before merging: bump purchasely/ios/purchasely_flutter.podspec + purchasely/ios/purchasely_flutter/Package.swift to 6.2.0 and add the VERSIONS.md row.

No native RunnerTests added: SwiftPurchaselyFlutterPluginTests.swift has no helper to drive handle(_:result:) and the private method isn't reachable otherwise.

Link to Devin session: https://app.devin.ai/sessions/af425686f98f4560a674a8e5f60cce47
Open in Devin Desktop: https://app.devin.ai/desktop/session/af425686f98f4560a674a8e5f60cce47?variant=devin
Requested by: @kherembourg

[devin-ai-integration]

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