Fix FAB overlapping send button in wide/tablet master-detail layout

In wide mode, the floating action button defaulted to bottom-right of
the screen, sitting on top of the chat send button and note detail pane.

Replace the FAB with a pinned ListTile at the bottom of the list pane
in wide mode (New conversation / New note). The FAB is still used on
narrow/phone screens where there is no overlap.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/screens/chat/conversations_list_screen.dart

@@ -52,18 +52,30 @@ class _ConversationsListScreenState
               children: [
                 SizedBox(
                   width: 300,
-                  child: _buildListPane(convsAsync, isWide),
+                  child: Column(
+                    children: [
+                      Expanded(child: _buildListPane(convsAsync, isWide)),
+                      const Divider(height: 1),
+                      ListTile(
+                        leading: const Icon(Icons.add),
+                        title: const Text('New conversation'),
+                        onTap: () => _newConversation(isWide),
+                      ),
+                    ],
+                  ),
                 ),
                 const VerticalDivider(width: 1),
                 Expanded(child: _buildDetailPane()),
               ],
             )
           : _buildListPane(convsAsync, isWide),
-      floatingActionButton: FloatingActionButton(
+      floatingActionButton: isWide
-        heroTag: 'chat_fab',
+          ? null
-        onPressed: () => _newConversation(isWide),
+          : FloatingActionButton(
-        child: const Icon(Icons.add),
+              heroTag: 'chat_fab',
-      ),
+              onPressed: () => _newConversation(isWide),
+              child: const Icon(Icons.add),
+            ),
     );
   }
 

lib/screens/notes/notes_list_screen.dart

@@ -35,18 +35,30 @@ class _NotesListScreenState extends ConsumerState<NotesListScreen> {
               children: [
                 SizedBox(
                   width: 300,
-                  child: _buildListPane(notesAsync, isWide),
+                  child: Column(
+                    children: [
+                      Expanded(child: _buildListPane(notesAsync, isWide)),
+                      const Divider(height: 1),
+                      ListTile(
+                        leading: const Icon(Icons.add),
+                        title: const Text('New note'),
+                        onTap: () => context.push(Routes.noteNew),
+                      ),
+                    ],
+                  ),
                 ),
                 const VerticalDivider(width: 1),
                 Expanded(child: _buildDetailPane()),
               ],
             )
           : _buildListPane(notesAsync, isWide),
-      floatingActionButton: FloatingActionButton(
+      floatingActionButton: isWide
-        heroTag: 'notes_fab',
+          ? null
-        onPressed: () => context.push(Routes.noteNew),
+          : FloatingActionButton(
-        child: const Icon(Icons.add),
+              heroTag: 'notes_fab',
-      ),
+              onPressed: () => context.push(Routes.noteNew),
+              child: const Icon(Icons.add),
+            ),
     );
   }