[webview_flutter] Register the iOS platform view with the hit-test gesture blocking policy

[burakimdatt]

Registers the iOS platform view with FlutterPlatformViewGestureRecognizersBlockingPolicyDoNotBlockGesture instead of relying on the default eager policy.

eager blocks the platform view's gesture recognizers through Flutter's gesture arena, which is stateful. If that state is stranded the web view stops receiving touches for the rest of its lifetime. The engine used to recover from this in ForwardingGestureRecognizer.forceResetStateIfNeeded, but that reset returns early on iOS 26 and above (see flutter/flutter#179907), so on iOS 26 there is nothing left to recover it.

doNotBlockGesture derives the same blocking decision from hitTest rather than the arena, and does not install the delaying recognizer at all — so there is no recognizer state to strand. Blocking behaviour itself is preserved: FlutterTouchInterceptingView.hitTest still consults platformViewShouldAcceptTouchAtTouchBeganLocation: and returns itself when a Flutter widget is on top, and the forwarding recognizer is still installed so Flutter's arena keeps seeing the touches.

Verified on iOS 26.3 simulator, iOS 26.4 simulator and an iOS 26.6 device: the web view is unresponsive after the first interaction without this change, and behaves correctly with it.

Fixes flutter/flutter#191261

Open question for the reviewer: this change is unconditional rather than gated behind if #available(iOS 26.0, *). I went that way because it is not iOS-26-specific in principle — the arena state can be stranded on any version, iOS 26 just removed the net that used to hide it — and because it matches the direction described in flutter/flutter#175099 ("help prevent regressions even if this WebKit bug happens again"). Happy to add a version gate instead if you would rather keep the blast radius smaller.

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[gemini-code-assist]

Code Review

This pull request updates WebViewFlutterPlugin.swift on iOS to register the web view factory using the FlutterPlatformViewGestureRecognizersBlockingPolicyDoNotBlockGesture policy. A corresponding unit test has been added to FWFWebViewFlutterWKWebViewExternalAPITests.swift to verify this policy registration, and the package version is bumped to 3.26.1 in pubspec.yaml and CHANGELOG.md. There are no review comments, so there is no feedback to provide.

[burakimdatt]

Closing this — I opened it from the wrong account. Reopening from the GitHub account associated with my signed CLA. Sorry for the noise.