feat: 添加应用品牌信息支持，重构主页 URL 生成逻辑

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

@@ -3,8 +3,13 @@ package io.openim.flutter.openim
 import android.content.Intent
 import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
+import android.graphics.Bitmap
+import android.graphics.Canvas
+import android.graphics.drawable.BitmapDrawable
+import android.graphics.drawable.Drawable
 import android.net.Uri
 import android.os.Build
+import android.util.Base64
 import android.util.Log
 import androidx.core.content.FileProvider
 import io.flutter.embedding.android.FlutterActivity
@@ -12,10 +17,12 @@ import org.conscrypt.Conscrypt
 import java.security.Security
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
+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 TAG = "MainActivity"
 
     override fun onCreate(savedInstanceState: android.os.Bundle?) {
@@ -80,6 +87,53 @@ class MainActivity : FlutterActivity() {
                 }
             }
         }
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, SHELL_BRANDING_CHANNEL).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "getShellBranding" -> {
+                    try {
+                        result.success(
+                            mapOf(
+                                "appName" to getCurrentAppName(),
+                                "appLogo" to getCurrentAppIconDataUrl()
+                            )
+                        )
+                    } catch (e: Exception) {
+                        result.error("ERROR", "无法获取当前应用品牌信息: ${e.message}", null)
+                    }
+                }
+                else -> {
+                    result.notImplemented()
+                }
+            }
+        }
+    }
+
+    private fun getCurrentAppName(): String {
+        val label = packageManager.getApplicationLabel(applicationInfo)
+        return label?.toString() ?: ""
+    }
+
+    private fun getCurrentAppIconDataUrl(): String {
+        val icon = packageManager.getApplicationIcon(packageName)
+        val bitmap = drawableToBitmap(icon)
+        val output = ByteArrayOutputStream()
+        bitmap.compress(Bitmap.CompressFormat.PNG, 100, output)
+        val base64 = Base64.encodeToString(output.toByteArray(), Base64.NO_WRAP)
+        return "data:image/png;base64,$base64"
+    }
+
+    private fun drawableToBitmap(drawable: Drawable): Bitmap {
+        if (drawable is BitmapDrawable && drawable.bitmap != null) {
+            return drawable.bitmap
+        }
+
+        val width = if (drawable.intrinsicWidth > 0) drawable.intrinsicWidth else 192
+        val height = if (drawable.intrinsicHeight > 0) drawable.intrinsicHeight else 192
+        val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
+        val canvas = Canvas(bitmap)
+        drawable.setBounds(0, 0, canvas.width, canvas.height)
+        drawable.draw(canvas)
+        return bitmap
     }
 
     private fun getApkPackageName(apkPath: String): String? {