redesign SourcesBlock: collapsed by default, vertical cards, clickable

Sources are now collapsed by default with a "Quellen (N)" header
that expands/collapses on tap (matching web's SourcesBlock behavior).

Each source renders as a full-width vertical card (not a small
140dp chip) with title, URL in accent color, and optional snippet.
Tapping a source opens it in the browser via ACTION_VIEW intent.

app/src/main/java/dev/kaizen/app/chat/StreamBlocks.kt

@@ -10,8 +10,6 @@ import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ExperimentalLayoutApi
-import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -50,6 +48,7 @@ import dev.kaizen.app.net.ToolEvent
 import dev.kaizen.app.R
 import dev.kaizen.app.ui.shape.KaizenShapes
 import dev.kaizen.app.ui.theme.LocalKaizenAccent
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 
 @Composable
@@ -170,36 +169,55 @@ fun ToolEventsBlock(tools: List<ToolEvent>, streaming: Boolean = false) {
     }
 }
 
-@OptIn(ExperimentalLayoutApi::class)
 @Composable
 fun SourcesBlock(sources: List<SearchSource>, query: String = "") {
     val cs = MaterialTheme.colorScheme
     val isDark = isSystemInDarkTheme()
+    val accent = LocalKaizenAccent.current
+    var expanded by remember { mutableStateOf(false) }
+    val context = LocalContext.current
 
     Column {
-        if (query.isNotBlank()) {
+        Row(
-            Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.padding(bottom = 6.dp)) {
+            Modifier
-                Icon(Icons.Rounded.Language, null, tint = cs.onSurfaceVariant, modifier = Modifier.size(14.dp))
+                .clickable { expanded = !expanded }
-                Spacer(Modifier.width(6.dp))
+                .padding(vertical = 4.dp),
-                Text(query, color = cs.onSurfaceVariant, fontSize = 12.sp, fontWeight = FontWeight.Medium)
+            verticalAlignment = Alignment.CenterVertically,
-            }
-        }
-        FlowRow(
-            horizontalArrangement = Arrangement.spacedBy(6.dp),
-            verticalArrangement = Arrangement.spacedBy(6.dp),
         ) {
-            sources.forEach { source ->
+            Icon(Icons.Rounded.Language, null, tint = cs.onSurfaceVariant.copy(alpha = 0.6f), modifier = Modifier.size(13.dp))
-                SourceChip(source, isDark)
+            Spacer(Modifier.width(6.dp))
+            Text(
+                stringResource(R.string.stream_sources) + " (${sources.size})",
+                color = cs.onSurfaceVariant.copy(alpha = 0.6f),
+                fontSize = 12.sp,
+                fontWeight = FontWeight.Medium,
+            )
+            Spacer(Modifier.width(4.dp))
+            Icon(
+                if (expanded) Icons.Rounded.ExpandLess else Icons.Rounded.ExpandMore,
+                null, tint = cs.onSurfaceVariant.copy(alpha = 0.4f), modifier = Modifier.size(12.dp),
+            )
+        }
+        AnimatedVisibility(expanded, enter = expandVertically(), exit = shrinkVertically()) {
+            Column(verticalArrangement = Arrangement.spacedBy(6.dp), modifier = Modifier.padding(top = 4.dp)) {
+                sources.forEach { source ->
+                    SourceCard(source, isDark, accent) {
+                        try {
+                            val intent = android.content.Intent(android.content.Intent.ACTION_VIEW, android.net.Uri.parse(source.url))
+                            context.startActivity(intent)
+                        } catch (_: Exception) { }
+                    }
+                }
             }
         }
     }
 }
 
 @Composable
-private fun SourceChip(source: SearchSource, isDark: Boolean) {
+private fun SourceCard(source: SearchSource, isDark: Boolean, accent: dev.kaizen.app.ui.theme.themes.KaizenAccentScheme, onClick: () -> Unit) {
     val cs = MaterialTheme.colorScheme
-    val bg = if (isDark) Color.White.copy(alpha = 0.06f) else Color.Black.copy(alpha = 0.04f)
+    val bg = if (isDark) Color.White.copy(alpha = 0.05f) else Color.Black.copy(alpha = 0.03f)
-    val borderColor = if (isDark) Color.White.copy(alpha = 0.08f) else Color.Black.copy(alpha = 0.06f)
+    val borderColor = if (isDark) Color.White.copy(alpha = 0.06f) else Color.Black.copy(alpha = 0.05f)
 
     val domain = remember(source.url) {
         try {
@@ -209,27 +227,38 @@ private fun SourceChip(source: SearchSource, isDark: Boolean) {
 
     Column(
         Modifier
-            .width(140.dp)
+            .fillMaxWidth()
-            .clip(KaizenShapes.xs)
+            .clip(KaizenShapes.sm)
             .background(bg)
-            .border(1.dp, borderColor, KaizenShapes.xs)
+            .border(1.dp, borderColor, KaizenShapes.sm)
-            .padding(horizontal = 10.dp, vertical = 8.dp),
+            .clickable(onClick = onClick)
+            .padding(horizontal = 12.dp, vertical = 10.dp),
     ) {
         Text(
             source.title.ifEmpty { domain },
             color = cs.onBackground,
-            fontSize = 12.sp,
+            fontSize = 13.sp,
             fontWeight = FontWeight.Medium,
             maxLines = 2,
             overflow = TextOverflow.Ellipsis,
         )
         Spacer(Modifier.height(2.dp))
         Text(
-            domain,
+            source.url,
-            color = cs.onSurfaceVariant.copy(alpha = 0.6f),
+            color = accent.primary.copy(alpha = 0.7f),
-            fontSize = 10.sp,
+            fontSize = 11.sp,
             maxLines = 1,
             overflow = TextOverflow.Ellipsis,
         )
+        if (source.snippet.isNotBlank()) {
+            Spacer(Modifier.height(3.dp))
+            Text(
+                source.snippet,
+                color = cs.onSurfaceVariant.copy(alpha = 0.5f),
+                fontSize = 11.sp,
+                maxLines = 2,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
     }
 }