fix(ios): Declare private initializers inline instead of importing private headers

Private headers (SentryBreadcrumb+Private.h, SentryUser+Private.h) are
not available in dynamic framework builds. Declare the category methods
inline to avoid the header-not-found error.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: antonis

packages/core/ios/RNSentry.mm

@@ -25,9 +25,12 @@
 #import <Sentry/SentryEvent.h>
 #import <Sentry/SentryException.h>
 #import <Sentry/SentryGeo.h>
-#import <Sentry/SentryUser+Private.h>
 #import <Sentry/SentryUser.h>
 
+@interface SentryUser ()
+- (instancetype)initWithDictionary:(NSDictionary *)dictionary;
+@end
+
 // This guard prevents importing Hermes in JSC apps
 #if SENTRY_PROFILING_ENABLED
 #    import <hermes/hermes.h>

packages/core/ios/RNSentryBreadcrumb.m

@@ -1,6 +1,9 @@
 #import "RNSentryBreadcrumb.h"
 @import Sentry;
-#import <Sentry/SentryBreadcrumb+Private.h>
+
+@interface SentryBreadcrumb ()
+- (instancetype _Nonnull)initWithDictionary:(NSDictionary *_Nonnull)dictionary;
+@end
 
 @implementation RNSentryBreadcrumb