Cover react/runtime with Stable API guards

Summary:
Classifies `react/runtime:runtime` and `react/runtime:runtime-platform` as "for frameworks" targets under the three-tier C++ stable API visibility model. Consumers that opt into `RN_STRICT_API` now get a warning if they include their headers directly, which they can acknowledge with `RN_ALLOW_FRAMEWORKS`; without that flag the guards are inert, so no existing build changes behaviour.

The Apple platform layer is covered alongside the core runtime, so `RCTHost.h` and `RCTInstance.h` are in scope. `React-RuntimeCore` already depended on `React-cxxstableapi` from an earlier migration in the same pod; `React-RuntimeApple` gains the dependency here.

Changelog: [Internal]

Differential Revision: D117690303

Author: j-piasecki

packages/react-native/ReactCommon/react/runtime/BindingsInstaller.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <react/runtime/ReactInstance.h>
 
 namespace facebook::react {

packages/react-native/ReactCommon/react/runtime/BridgelessNativeMethodCallInvoker.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <ReactCommon/CallInvoker.h>
 #include <cxxreact/MessageQueueThread.h>
 #include <memory>

packages/react-native/ReactCommon/react/runtime/BufferedRuntimeExecutor.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <ReactCommon/RuntimeExecutor.h>
 #include <jsi/jsi.h>
 #include <atomic>

packages/react-native/ReactCommon/react/runtime/CMakeLists.txt

@@ -34,6 +34,7 @@ target_link_libraries(
         jsi
         jsitooling
         jsireact
+        react_cxxstableapi
         react_utils
         jsinspector
         react_featureflags

packages/react-native/ReactCommon/react/runtime/PlatformTimerRegistry.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <cstdint>
 #include <memory>
 

packages/react-native/ReactCommon/react/runtime/ReactInstance.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <ReactCommon/RuntimeExecutor.h>
 #include <cxxreact/JSBigString.h>
 #include <cxxreact/MessageQueueThread.h>

packages/react-native/ReactCommon/react/runtime/TimerManager.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #include <ReactCommon/RuntimeExecutor.h>
 #include <unordered_map>
 #include <vector>

packages/react-native/ReactCommon/react/runtime/platform/ios/React-RuntimeApple.podspec

@@ -55,6 +55,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jserrorhandler"
   s.dependency "React-jsinspector"
   s.dependency "React-featureflags"
+  s.dependency "React-cxxstableapi"
   add_dependency(s, "React-jsitooling", :framework_name => "JSITooling")
   add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "React-utils", :additional_framework_paths => ["react/utils/platform/ios"])

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/ObjCTimerRegistry.h

@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #import <UIKit/UIKit.h>
 
 #import <React/RCTTiming.h>

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTContextContainerHandling.h

@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+#include <react/cxxstableapi/FrameworksGuard.h>
+
 #import <Foundation/Foundation.h>
 
 #import <react/utils/ContextContainer.h>