killing of the buffers now works

client/src/state/app/buffer.rs

@@ -64,20 +64,27 @@ impl BufferState {
         self.history.get(self.active_index)
     }
 
-    /// Removes the currently active buffer from the history.
+    /// Removes the currently active buffer from the history, unless it's the Intro buffer.
     /// Sets the new active buffer to the one preceding the closed one.
-    /// Returns `true` if a buffer was closed, `false` otherwise (e.g., only one buffer left).
+    /// # Returns
+    /// * `true` if a non-Intro buffer was closed.
+    /// * `false` if the active buffer was Intro or only Intro remained.
     pub fn close_active_buffer(&mut self) -> bool {
-        if self.history.len() <= 1 {
-            return false; // Cannot close the last buffer
+        let current_index = self.active_index;
+
+        // Rule 1: Cannot close Intro buffer.
+        if matches!(self.history.get(current_index), Some(AppView::Intro)) {
+            return false;
         }
 
-        let current_index = self.active_index;
-        self.history.remove(current_index); // Remove the active buffer
+        // Rule 2: Cannot close if only Intro would remain (or already remains).
+        // This check implicitly covers the case where len <= 1.
+        if self.history.len() <= 1 {
+             return false;
+        }
 
-        // Set the new active index to the one *before* the closed one,
-        // ensuring it doesn't go below 0. This mimics closing a tab.
-        self.active_index = current_index.saturating_sub(1);
+        self.history.remove(current_index);
+        self.active_index = current_index.saturating_sub(1).min(self.history.len() - 1);
 
         true
     }