fix(android): show backdrop behind WebView

apps/android/app/src/main/java/com/steipete/clawdis/node/ui/RootScreen.kt

@@ -4,10 +4,15 @@ import android.annotation.SuppressLint
 import android.Manifest
 import android.content.pm.PackageManager
 import android.graphics.Color
+import android.util.Log
 import android.view.View
 import android.webkit.WebView
 import android.webkit.WebSettings
+import android.webkit.WebResourceError
+import android.webkit.WebResourceRequest
+import android.webkit.WebResourceResponse
 import android.webkit.WebViewClient
+import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -19,6 +24,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.safeDrawing
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.windowInsetsPadding
+import androidx.compose.foundation.background
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.FilledTonalIconButton
 import androidx.compose.material3.Icon
@@ -36,7 +42,10 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color as ComposeColor
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.viewinterop.AndroidView
@@ -71,6 +80,7 @@ fun RootScreen(viewModel: MainViewModel) {
       PackageManager.PERMISSION_GRANTED
 
   Box(modifier = Modifier.fillMaxSize()) {
+    CanvasBackdrop(modifier = Modifier.fillMaxSize())
     CanvasView(viewModel = viewModel, modifier = Modifier.fillMaxSize())
   }
 
@@ -143,6 +153,7 @@ private fun OverlayIconButton(
 @Composable
 private fun CanvasView(viewModel: MainViewModel, modifier: Modifier = Modifier) {
   val context = LocalContext.current
+  val isDebuggable = (context.applicationInfo.flags and android.content.pm.ApplicationInfo.FLAG_DEBUGGABLE) != 0
   AndroidView(
     modifier = modifier,
     factory = {
@@ -151,12 +162,98 @@ private fun CanvasView(viewModel: MainViewModel, modifier: Modifier = Modifier)
         // Some embedded web UIs (incl. the "background website") use localStorage/sessionStorage.
         settings.domStorageEnabled = true
         settings.mixedContentMode = WebSettings.MIXED_CONTENT_COMPATIBILITY_MODE
-        webViewClient = WebViewClient()
+        webViewClient =
+          object : WebViewClient() {
+            override fun onReceivedError(
+              view: WebView,
+              request: WebResourceRequest,
+              error: WebResourceError,
+            ) {
+              if (!isDebuggable) return
+              if (!request.isForMainFrame) return
+              Log.e("ClawdisWebView", "onReceivedError: ${error.errorCode} ${error.description} ${request.url}")
+            }
+
+            override fun onReceivedHttpError(
+              view: WebView,
+              request: WebResourceRequest,
+              errorResponse: WebResourceResponse,
+            ) {
+              if (!isDebuggable) return
+              if (!request.isForMainFrame) return
+              Log.e(
+                "ClawdisWebView",
+                "onReceivedHttpError: ${errorResponse.statusCode} ${errorResponse.reasonPhrase} ${request.url}",
+              )
+            }
+          }
         setBackgroundColor(Color.TRANSPARENT)
         setBackgroundResource(0)
-        setLayerType(View.LAYER_TYPE_HARDWARE, null)
+        // WebView transparency + HW acceleration can render as solid black on some Android/WebView builds.
+        // Prefer correct alpha blending since we render the idle backdrop in Compose underneath.
+        setLayerType(View.LAYER_TYPE_SOFTWARE, null)
         viewModel.canvas.attach(this)
       }
     },
   )
 }
+
+@Composable
+private fun CanvasBackdrop(modifier: Modifier = Modifier) {
+  val base = MaterialTheme.colorScheme.background
+
+  Canvas(modifier = modifier.background(base)) {
+    // Subtle idle backdrop; also acts as fallback when WebView content is transparent or fails to load.
+    drawRect(
+      brush =
+        Brush.linearGradient(
+          colors =
+            listOf(
+              ComposeColor(0xFF0A2034),
+              ComposeColor(0xFF070A10),
+              ComposeColor(0xFF250726),
+            ),
+          start = Offset(0f, 0f),
+          end = Offset(size.width, size.height),
+        ),
+    )
+
+    val step = 48f * density
+    val lineColor = ComposeColor.White.copy(alpha = 0.028f)
+    var x = -step
+    while (x < size.width + step) {
+      drawLine(color = lineColor, start = Offset(x, 0f), end = Offset(x, size.height), strokeWidth = 1f)
+      x += step
+    }
+    var y = -step
+    while (y < size.height + step) {
+      drawLine(color = lineColor, start = Offset(0f, y), end = Offset(size.width, y), strokeWidth = 1f)
+      y += step
+    }
+
+    drawRect(
+      brush =
+        Brush.radialGradient(
+          colors = listOf(ComposeColor(0xFF2A71FF).copy(alpha = 0.22f), ComposeColor.Transparent),
+          center = Offset(size.width * 0.15f, size.height * 0.20f),
+          radius = size.minDimension * 0.9f,
+        ),
+    )
+    drawRect(
+      brush =
+        Brush.radialGradient(
+          colors = listOf(ComposeColor(0xFFFF008A).copy(alpha = 0.18f), ComposeColor.Transparent),
+          center = Offset(size.width * 0.85f, size.height * 0.30f),
+          radius = size.minDimension * 0.75f,
+        ),
+    )
+    drawRect(
+      brush =
+        Brush.radialGradient(
+          colors = listOf(ComposeColor(0xFF00D1FF).copy(alpha = 0.14f), ComposeColor.Transparent),
+          center = Offset(size.width * 0.60f, size.height * 0.90f),
+          radius = size.minDimension * 0.85f,
+        ),
+    )
+  }
+}

apps/android/app/src/main/res/xml/network_security_config.xml

@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <network-security-config>
+  <!-- This app is primarily used on a trusted tailnet; allow cleartext for IP-based endpoints too. -->
+  <base-config cleartextTrafficPermitted="true" />
   <!-- Allow HTTP for tailnet/local dev endpoints (e.g. canvas/background web). -->
   <domain-config cleartextTrafficPermitted="true">
     <domain includeSubdomains="true">clawdis.internal</domain>