feat: 添加 WebView 无缓存配置和运行时缓存清理逻辑，优化页面加载体验

android/app/src/main/kotlin/io/openim/flutter/openim/MainActivity.kt

@@ -11,18 +11,22 @@ import android.net.Uri
 import android.os.Build
 import android.util.Base64
 import android.util.Log
+import android.webkit.ServiceWorkerController
+import android.webkit.WebSettings
 import androidx.core.content.FileProvider
 import io.flutter.embedding.android.FlutterActivity
 import org.conscrypt.Conscrypt
 import java.security.Security
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
+import io.flutter.plugins.webviewflutter.WebViewFlutterAndroidExternalApi
 import java.io.ByteArrayOutputStream
 import java.io.File
 
 class MainActivity : FlutterActivity() {
     private val CHANNEL = "io.openim.flutter.openim/apk_info"
     private val SHELL_BRANDING_CHANNEL = "io.openim.flutter.im_webview_app/shell_branding"
+    private val WEBVIEW_CACHE_CHANNEL = "io.openim.flutter.im_webview_app/webview_cache"
     private val TAG = "MainActivity"
     private val MAX_BRANDING_ICON_SIZE = 192
 
@@ -107,6 +111,55 @@ class MainActivity : FlutterActivity() {
                 }
             }
         }
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, WEBVIEW_CACHE_CHANNEL).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "configureNoCache" -> {
+                    val webViewId = readLongArgument(call.argument<Any>("webViewId"))
+                    if (webViewId == null) {
+                        result.error("INVALID_ARGUMENT", "webViewId 不能为空", null)
+                        return@setMethodCallHandler
+                    }
+
+                    try {
+                        result.success(configureWebViewNoCache(flutterEngine, webViewId))
+                    } catch (e: Exception) {
+                        result.error("ERROR", "无法配置 WebView 缓存策略: ${e.message}", null)
+                    }
+                }
+                else -> {
+                    result.notImplemented()
+                }
+            }
+        }
+    }
+
+    private fun readLongArgument(value: Any?): Long? {
+        return when (value) {
+            is Int -> value.toLong()
+            is Long -> value
+            is Number -> value.toLong()
+            else -> null
+        }
+    }
+
+    private fun configureWebViewNoCache(flutterEngine: FlutterEngine, webViewId: Long): Boolean {
+        val webView = WebViewFlutterAndroidExternalApi.getWebView(flutterEngine, webViewId) ?: return false
+
+        webView.settings.cacheMode = WebSettings.LOAD_NO_CACHE
+        webView.clearCache(true)
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            try {
+                ServiceWorkerController
+                    .getInstance()
+                    .serviceWorkerWebSettings
+                    .cacheMode = WebSettings.LOAD_NO_CACHE
+            } catch (e: Exception) {
+                Log.w(TAG, "ServiceWorker cache mode configure failed: ${e.message}")
+            }
+        }
+
+        return true
     }
 
     private fun getCurrentAppName(): String {