gui: render user-interrupt with yellow background and warning icon

- Add Interrupt block type to ChatBlock enum
- Detect <system-user-interruption> and </system-user-interruption>
  tags as block openers/closers in the parser
- Render interrupt blocks with bright yellow header
  (#3d2e00 dark, #fff8e1 light)
- Show ⚠ User Interrupt header label

gui/chatblockmodel.cpp

@@ -49,6 +49,12 @@ const QRegularExpression ChatBlockModel::s_headerRe(
 const QRegularExpression ChatBlockModel::s_endRe(
     R"(^\[\[\[end\]\]\]$)");
 
+const QRegularExpression ChatBlockModel::s_interruptOpenRe(
+    R"(^<system-user-interruption>\s*$)");
+
+const QRegularExpression ChatBlockModel::s_interruptCloseRe(
+    R"(^</system-user-interruption>\s*$)");
+
 ChatBlockModel::ChatBlockModel(QObject *parent)
     : QAbstractListModel(parent)
 {
@@ -74,10 +80,11 @@ QVariant ChatBlockModel::data(const QModelIndex &index, int role) const
 	        case ChatBlock::Reasoning: return QStringLiteral("reasoning");
 	        case ChatBlock::Call:      return QStringLiteral("call");
 	        case ChatBlock::Tool:      return QStringLiteral("tool");
-	        case ChatBlock::Error:     return QStringLiteral("error");
-	        case ChatBlock::Info:      return QStringLiteral("info");
-	        case ChatBlock::Retry:     return QStringLiteral("retry");
-	        case ChatBlock::Default:   return QStringLiteral("default");
+case ChatBlock::Error:     return QStringLiteral("error");
+		        case ChatBlock::Info:      return QStringLiteral("info");
+		        case ChatBlock::Retry:     return QStringLiteral("retry");
+		        case ChatBlock::Interrupt: return QStringLiteral("interrupt");
+		        case ChatBlock::Default:   return QStringLiteral("default");
 	        }
         return {};
     case BlockNameRole:
@@ -235,6 +242,12 @@ void ChatBlockModel::processLine(const QString &line)
         return;
     }
 
+    // --- Interrupt close tag ---
+    if (s_interruptCloseRe.match(line).hasMatch()) {
+        m_inBlock = false;
+        return;
+    }
+
     // --- NoFence state: look for opening fence or header ---
     static const QRegularExpression fenceOpenRe(R"(^```(\w*)[ \t]*$)");
     QRegularExpressionMatch fenceMatch = fenceOpenRe.match(line);
@@ -254,6 +267,16 @@ void ChatBlockModel::processLine(const QString &line)
         return;
     }
 
+    // Interrupt open tag — creates its own block
+    if (s_interruptOpenRe.match(line).hasMatch()) {
+        beginInsertRows(QModelIndex(), m_blocks.size(), m_blocks.size());
+        m_blocks.append({ChatBlock::Interrupt, QString(), QString(), QString()});
+        endInsertRows();
+        emit countChanged();
+        m_inBlock = true;
+        return;
+    }
+
     // Header line
     QRegularExpressionMatch m = s_headerRe.match(line);
     if (m.hasMatch()) {

gui/chatblockmodel.h

@@ -16,6 +16,7 @@ struct ChatBlock {
         Error,
         Info,
         Retry,
+        Interrupt,
         Default
     };
 
@@ -75,6 +76,8 @@ private:
 
     static const QRegularExpression s_headerRe;
     static const QRegularExpression s_endRe;
+    static const QRegularExpression s_interruptOpenRe;
+    static const QRegularExpression s_interruptCloseRe;
 };
 
 #endif // CHATBLOCKMODEL_H

gui/main.qml

@@ -727,16 +727,17 @@ delegate: ColumnLayout {
                         width: chatView.width - 8
                         spacing: 2
 
-		                    property bool blockExpanded: {
-		                        switch (blockType) {
-		                        case "user":      return true
-		                        case "assistant": return true
-		                        case "tool":      return true
-		                        case "info":      return true
-		                        case "retry":     return true
-		                        default:          return false
-		                        }
-		                    }
+property bool blockExpanded: {
+                        switch (blockType) {
+                        case "user":      return true
+                        case "assistant": return true
+                        case "tool":      return true
+                        case "info":      return true
+                        case "retry":     return true
+                        case "interrupt": return true
+                        default:          return false
+                        }
+                    }
 
                         // Clickable header
         Rectangle {
@@ -755,6 +756,7 @@ delegate: ColumnLayout {
 	                    case "error":     return Qt.rgba(0.6, 0.15, 0.15, 0.7)
 	                    case "info":      return Qt.lighter(bg, 1.4)
 	                    case "retry":     return Qt.rgba(0.6, 0.5, 0.0, 0.5)
+	                    case "interrupt": return "#3d2e00"
 	                    default:          return bg
 	                    }
 	                } else {
@@ -767,6 +769,7 @@ delegate: ColumnLayout {
 	                    case "error":     return Qt.rgba(1.0, 0.8, 0.8, 0.7)
 	                    case "info":      return Qt.darker(bg, 1.02)
 	                    case "retry":     return Qt.rgba(1.0, 0.9, 0.6, 0.5)
+	                    case "interrupt": return "#fff8e1"
 	                    default:          return bg
 	                    }
 	                }
@@ -801,6 +804,7 @@ delegate: ColumnLayout {
 	                        case "error":     return "Error"
 	                        case "info":      return "Info"
 	                        case "retry":     return "Retry"
+	                        case "interrupt": return "\u26A0 User Interrupt"
 	                        default:          return ""
 	                        }
 	                    }