build(metro): add web shims for native React Native API compatibility

Add Metro configuration to resolve native-only React Native APIs with web-compatible shims. This enables packages like react-native-pager-view to work on the web platform by providing shim implementations for codegenNativeComponent, codegenNativeCommands, and CodegenTypes that are unavailable in react-native-web.

Also simplify Android signing configuration in CI by using standard Gradle property names (MYAPP_UPLOAD_*) and remove the build.gradle patching step.

web-shims/react-native/Libraries/Types/CodegenTypes.js

@@ -0,0 +1,17 @@
+const Double = Number;
+const Int32 = Number;
+const Float = Number;
+const WithDefault = (type, defaultValue) => type;
+
+module.exports = {
+  Double,
+  Float,
+  Int32,
+  WithDefault,
+  DirectEventHandler: () => null,
+  BubblingEventHandler: () => null,
+  Stringish: String,
+  ColorValue: null,
+  HandledState: String,
+  WithSpringAnimation: (type) => type,
+};

web-shims/react-native/Libraries/Utilities/codegenNativeCommands.js

@@ -0,0 +1,15 @@
+function codegenNativeCommands(options) {
+  const commands = {};
+  if (options && options.supportedCommands) {
+    options.supportedCommands.forEach((commandName) => {
+      commands[commandName] = (ref, ...args) => {
+        if (ref && ref.current && typeof ref.current[commandName] === 'function') {
+          ref.current[commandName](...args);
+        }
+      };
+    });
+  }
+  return commands;
+}
+
+module.exports = codegenNativeCommands;

web-shims/react-native/Libraries/Utilities/codegenNativeComponent.js

@@ -0,0 +1,18 @@
+const React = require('react');
+
+function codegenNativeComponent(componentName, options) {
+  const componentNameClean = componentName
+    .replace(/^RNC/, '')
+    .replace(/^RNS/, '')
+    .replace(/^RN/, '');
+
+  const NativeComponent = React.forwardRef((props, ref) => {
+    const { children, ...rest } = props;
+    return React.createElement('div', { ...rest, ref, 'data-native-component': componentNameClean }, children);
+  });
+  NativeComponent.displayName = componentName;
+
+  return NativeComponent;
+}
+
+module.exports = codegenNativeComponent;