refactored lesson details, centralized logout logic, and added resume re-fetch

lib/view/pages/talk/data/chat_bubble_styles.dart

@@ -24,7 +24,6 @@ class ChatBubbleStyles {
 
   BubbleStyle getSystemStyle() => BubbleStyle(
     color: AppTheme.isDarkMode(context) ? const Color(0xff182229) : Colors.white,
-    borderWidth: 1,
     elevation: 2,
     margin: const BubbleEdges.only(bottom: 20, top: 10),
     alignment: Alignment.center,
@@ -35,7 +34,6 @@ class ChatBubbleStyles {
     return BubbleStyle(
       nip: BubbleNip.leftTop,
       color: seamless ? Colors.transparent : color,
-      borderWidth: seamless ? 0 : 1,
       elevation: seamless ? 0 : 1,
       margin: const BubbleEdges.only(bottom: 10, left: 10, right: 50),
       alignment: Alignment.topLeft,
@@ -47,7 +45,6 @@ class ChatBubbleStyles {
     return BubbleStyle(
       nip: BubbleNip.rightBottom,
       color: seamless ? Colors.transparent : color,
-      borderWidth: seamless ? 0 : 1,
       elevation: seamless ? 0 : 1,
       margin: const BubbleEdges.only(bottom: 10, right: 10, left: 50),
       alignment: Alignment.topRight,