show context panel on decision/ticket selection

The context panel was hidden or collapsed when a decision or ticket
was selected. activateTab alone doesn't make the panel visible.
Now both extensions explicitly setVisible + setCollapsed before
activating the detail tab.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/builtin/decisions/src/extension.dart

@@ -32,6 +32,8 @@ class DecisionsExtension extends ClideExtension {
         icon: PhosphorIcons.lightbulb,
         build: (_) => DecisionDetailView(initialId: selectedId),
       ));
+      ctx.arrangement.setVisible(Slots.contextPanel, true);
+      ctx.arrangement.setCollapsed(Slots.contextPanel, false);
       ctx.panels.activateTab(Slots.contextPanel, 'decisions.detail');
     });
   }

lib/builtin/tickets/src/extension.dart

@@ -32,6 +32,8 @@ class TicketsExtension extends ClideExtension {
         icon: PhosphorIcons.ticket,
         build: (_) => TicketDetailView(initialId: selectedId),
       ));
+      ctx.arrangement.setVisible(Slots.contextPanel, true);
+      ctx.arrangement.setCollapsed(Slots.contextPanel, false);
       ctx.panels.activateTab(Slots.contextPanel, 'tickets.detail');
     });
   }