feat: Enhance ImageAttachment placeholder with gradient background and improved blurhash logging

app/src/main/java/com/rosetta/messenger/ui/chats/components/AttachmentComponents.kt

@@ -22,6 +22,7 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.graphics.drawscope.Stroke
@@ -172,14 +173,22 @@ fun ImageAttachment(
         }
         
         // Декодируем blurhash для placeholder (если есть)
-        if (preview.length >= 20) {
+        if (preview.isNotEmpty() && !isDownloadTag(preview)) {
             withContext(Dispatchers.IO) {
                 try {
+                    Log.d(TAG, "🎨 Decoding blurhash: ${preview.take(30)}... (length: ${preview.length})")
                     blurhashBitmap = BlurHash.decode(preview, 200, 200)
+                    if (blurhashBitmap != null) {
+                        Log.d(TAG, "✅ Blurhash decoded successfully")
+                    } else {
+                        Log.w(TAG, "⚠️ Blurhash decode returned null")
+                    }
                 } catch (e: Exception) {
-                    Log.e(TAG, "Failed to decode blurhash: ${e.message}")
+                    Log.e(TAG, "❌ Failed to decode blurhash: ${e.message}", e)
                 }
             }
+        } else {
+            Log.d(TAG, "⚠️ No valid blurhash preview (preview='${preview.take(20)}...', isDownloadTag=${isDownloadTag(preview)})")
         }
         
         // Декодируем изображение если уже скачано
@@ -318,11 +327,18 @@ fun ImageAttachment(
                 )
             }
             else -> {
-                // Простой placeholder
+                // Простой placeholder с приятным gradient фоном
                 Box(
                     modifier = Modifier
                         .fillMaxSize()
-                        .background(if (isDarkTheme) Color(0xFF2A2A2A) else Color(0xFFE8E8E8))
+                        .background(
+                            Brush.verticalGradient(
+                                colors = if (isDarkTheme) 
+                                    listOf(Color(0xFF2A2A2A), Color(0xFF1A1A1A))
+                                else 
+                                    listOf(Color(0xFFE8E8E8), Color(0xFFD0D0D0))
+                            )
+                        )
                 )
             }
         }