Migrate iOS enableUnhandledCPPExceptionsV2 off the deprecated experimental alias #6783

Description

sentry-cocoa #9134 promotes enableUnhandledCPPExceptionsV2 from SentryOptions.experimental up to a top-level SentryOptions property. The old experimental.enableUnhandledCPPExceptionsV2 is kept as a shared-value deprecated alias and, per the deprecation annotation, will be removed in the next cocoa minor release.

The RN SDK reads and writes this option in packages/core/ios/RNSentryExperimentalOptions.m:

sentryOptions.experimental.enableUnhandledCPPExceptionsV2 = enabled;   // setter
return sentryOptions.experimental.enableUnhandledCPPExceptionsV2;       // getter

Impact

• At the cocoa release that ships #9134 (a v9 minor): RN still compiles and behaves identically — the alias shares the same backing value — but these two lines will emit deprecation warnings (the ObjC property gains DEPRECATED_MSG_ATTRIBUTE).
• At the following cocoa minor, where the alias is removed: sentryOptions.experimental.enableUnhandledCPPExceptionsV2 will fail to compile.

We currently bundle cocoa 9.29.0, so there is no runtime breakage today. This is a tracking issue to migrate ahead of the removal.

Action

Switch to the top-level property (exposed on the ObjC wrapper SentryObjCOptions.h) at the next cocoa bump that contains #9134:

sentryOptions.enableUnhandledCPPExceptionsV2 = enabled;
return sentryOptions.enableUnhandledCPPExceptionsV2;

• Behavior is identical; the top-level property exists in the same release, so this also clears the deprecation warning immediately.
• The JS _experiments.enableUnhandledCPPExceptionsV2 key and RN's public API stay unchanged — this is purely the native mapping in RNSentryExperimentalOptions.m.

References

• sentry-cocoa PR: feat: Promote experimental options to stable sentry-cocoa#9134