fix sidebar order and ptyc status bar warning

Revert priority sort in tabsFor() — registration order in
main.dart is the intended sidebar order, not priority. The
priority fields on extensions were dead code.

Remove ptyc from toolchain missing list since NativePty
replaced it.

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

lib/kernel/src/panels/registry.dart

@@ -68,14 +68,11 @@ class PanelRegistry extends ChangeNotifier {
   List<TabContribution> tabsFor(SlotId id) {
     final tabs = contributionsFor(id).whereType<TabContribution>().toList();
     final order = _order[id];
-    if (order == null || order.isEmpty) {
-      tabs.sort((a, b) => a.priority.compareTo(b.priority));
-      return tabs;
-    }
+    if (order == null || order.isEmpty) return tabs;
     tabs.sort((a, b) {
       final ai = order.indexOf(a.id);
       final bi = order.indexOf(b.id);
-      if (ai < 0 && bi < 0) return a.priority.compareTo(b.priority);
+      if (ai < 0 && bi < 0) return 0;
       if (ai < 0) return 1;
       if (bi < 0) return -1;
       return ai.compareTo(bi);

lib/kernel/src/toolchain.dart

@@ -54,7 +54,6 @@ class Toolchain extends ChangeNotifier {
         if (_git == null) 'git',
         if (_pql == null) 'pql',
         if (_tmux == null) 'tmux',
-        if (_ptyc == null) 'ptyc',
       ];
 
   /// Returns a Future that completes when resolution finishes.