websocket comms console widget

pi/ui/lib/widgets/debug_console.dart

@@ -0,0 +1,72 @@
+import 'dart:async';
+import 'package:flutter/material.dart';
+
+import '../services/websocket_service.dart';
+import '../theme/app_theme.dart';
+
+/// Self-contained debug console that displays WebSocket log messages.
+/// Subscribes to WebSocketService.debugStream internally.
+class DebugConsole extends StatefulWidget {
+  /// Maximum lines to display
+  final int maxLines;
+
+  const DebugConsole({
+    super.key,
+    this.maxLines = 8,
+  });
+
+  @override
+  State<DebugConsole> createState() => _DebugConsoleState();
+}
+
+class _DebugConsoleState extends State<DebugConsole> {
+  final List<String> _messages = [];
+  StreamSubscription<String>? _debugSub;
+
+  @override
+  void initState() {
+    super.initState();
+
+    // Initialize with existing buffer
+    _messages.addAll(WebSocketService.instance.debugMessages);
+    _trimMessages();
+
+    // Subscribe to new messages
+    _debugSub = WebSocketService.instance.debugStream.listen((msg) {
+      setState(() {
+        _messages.add(msg);
+        _trimMessages();
+      });
+    });
+  }
+
+  void _trimMessages() {
+    while (_messages.length > widget.maxLines) {
+      _messages.removeAt(0);
+    }
+  }
+
+  @override
+  void dispose() {
+    _debugSub?.cancel();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = AppTheme.of(context);
+
+    return Container(
+      padding: const EdgeInsets.all(4),
+      child: Text(
+        _messages.isEmpty ? '(no messages)' : _messages.join('\n'),
+        style: TextStyle(
+          fontFamily: 'monospace',
+          fontSize: 34,
+          color: theme.foreground,
+          height: 1.2,
+        ),
+      ),
+    );
+  }
+}