feat: sync httpdns sdk/platform updates without large binaries

HttpDNSSDK/sdk/flutter/new_httpdns/example/README.md

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+# TrustAPP_httpdns_example
+
+Demonstrates how to use the TrustAPP_httpdns plugin with various network libraries.
+
+## Features
+
+This example demonstrates:
+- HTTPDNS initialization and configuration
+- Domain name resolution (IPv4 and IPv6)
+- Integration with multiple network libraries:
+  - Dio
+  - HttpClient
+  - http package
+- Custom HTTP client adapter for HTTPDNS
+- Real HTTP requests using HTTPDNS resolution
+
+## Getting Started
+
+1. Replace the SDK init parameters in `lib/main.dart` with your own values:
+   ```dart
+   await TrustAPPHttpdns.init(
+     appId: 'YOUR_APP_ID',
+     primaryServiceHost: 'httpdns-a.example.com',
+     backupServiceHost: 'httpdns-b.example.com',
+     servicePort: 443,
+     secretKey: 'YOUR_SIGN_SECRET', // optional if sign is enabled
+   );
+   ```
+
+2. Install dependencies:
+   ```bash
+   flutter pub get
+   ```
+
+3. Run the app:
+   ```bash
+   flutter run
+   ```
+
+4. Try the features:
+   - Enter a URL and select a network library (Dio/HttpClient/http)
+   - Tap "Send Request" to make an HTTP request using HTTPDNS
+   - Tap "HTTPDNS Resolve" to test domain resolution directly
+
+## Implementation Details
+
+The example uses a modern approach with `HttpClient.connectionFactory` to integrate HTTPDNS:
+- See `lib/net/httpdns_http_client_adapter.dart` for the implementation
+- This approach avoids the complexity of local proxy servers
+- Works seamlessly with Dio, HttpClient, and http package
+
+## Note
+
+The values in this example are placeholders. Use your own platform app configuration.