refactor: remove unused old dashbot features and related files

lib/dashbot/widgets/chat_bubble.dart

@@ -1,54 +0,0 @@
-// lib/dashbot/widgets/chat_bubble.dart
-import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
-import 'content_renderer.dart';
-
-class ChatBubble extends StatelessWidget {
-  final String message;
-  final bool isUser;
-
-  const ChatBubble({
-    super.key,
-    required this.message,
-    this.isUser = false,
-  });
-
-  @override
-  Widget build(BuildContext context) {
-    return Align(
-      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
-      child: Container(
-        margin: const EdgeInsets.symmetric(vertical: 4, horizontal: 12),
-        padding: const EdgeInsets.all(12),
-        decoration: BoxDecoration(
-          color: isUser
-              ? Theme.of(context).colorScheme.primaryContainer
-              : Theme.of(context).colorScheme.surfaceContainerHighest,
-          borderRadius: BorderRadius.circular(8),
-        ),
-        child: Row(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Flexible(
-              child: renderContent(context, message),
-            ),
-            if (!isUser) ...[
-              const SizedBox(width: 8),
-              IconButton(
-                icon: const Icon(Icons.copy, size: 20),
-                tooltip: 'Copy Response',
-                onPressed: () {
-                  Clipboard.setData(ClipboardData(text: message));
-                  ScaffoldMessenger.of(context).showSnackBar(
-                    const SnackBar(content: Text('Copied to clipboard')),
-                  );
-                },
-              ),
-            ],
-          ],
-        ),
-      ),
-    );
-  }
-}