chore(comments): drop the spec task codes the last pass missed

Codes like POP-1c or B4b-2 name a task in a planning document, not
anything in the code. A reader has no way to resolve them and they age
into noise the moment the document is closed. Where a code was used as a
reference, the sentence now names the function it meant.

HellionChat/Ui/Components/TopTabBar.cs

@@ -52,7 +52,7 @@ internal sealed class TopTabBar
         for (var i = 0; i < tabs.Count; i++)
         {
             var tab = tabs[i];
-            // POP-1b: a popped-out tab is owned by its pop-out window, not the main
+            // A popped-out tab is owned by its pop-out window, not the main
             // strip (1.5.6 exclusivity). Gate on the pool, not Tab.PopOut (stale flag).
             if (_pool.IsOpen(tab.Identifier))
                 continue;

HellionChat/Ui/Windows/ChannelPopoutWindow.cs

@@ -155,7 +155,7 @@ internal sealed class ChannelPopoutWindow : Window, IFocusableChatWindow
         if (Bound is null)
             return;
 
-        // POP-1f: the bound tab is live-visible in this pop-out, so it carries no
+        // The bound tab is live-visible in this pop-out, so it carries no
         // unread badge — mirror MainWindow's per-frame zero for the active tab.
         // View-state reset only (tab.Messages store is untouched).
         Bound.Unread = 0;

HellionChat/Ui/Windows/MainWindow.cs

@@ -310,9 +310,9 @@ internal sealed class MainWindow : Window, IFocusableChatWindow
                 TabLifecycleHelpers.OnTabActivated(reseed, active);
         }
 
-        // POP-1c: a popped-out tab must not stay the main window's active surface
+        // A popped-out tab must not stay the main window's active surface
         // (1.5.6 exclusivity). Re-anchor to the first non-popped tab the moment the
-        // active one is popped; null when every tab is popped (POP-1d guards Draw).
+        // active one is popped; null when every tab is popped, which Draw guards for.
         // Runs post-seed, before the sidebar/top-tab draw, so the popped tab never
         // renders. Idempotent: PickMainActiveTab returns the same reference once
         // settled, so OnTabActivated fires only on the pop frame.