tui: add /session command to list available sessions

packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx

@@ -240,6 +240,11 @@ export function Autocomplete(props: {
         description: "list agents",
         onSelect: () => command.trigger("agent.list"),
       },
+      {
+        display: "/session",
+        description: "list sessions",
+        onSelect: () => command.trigger("session.list"),
+      },
       {
         display: "/status",
         description: "show status",