Gateway: keep whole T3 history pages, and show a command's first line as its activity

gateway/test/views.test.ts

@@ -239,11 +239,11 @@ describe("currentActivity", () => {
     expect(
       currentActivity([
         item("file_change", "running", { fileName: "gateway/src/host.ts" }),
-        item("command_execution", "running", { input: "bun test" }),
+        item("command_execution", "running", { input: "\nbun test \\\n  --bail" }),
         item("command_execution", "running", { input: "tail -f log", monitor: true }),
         item("assistant_message", "running"),
       ]),
-    ).toEqual({ kind: "command", text: "bun test", startedAt: "2026-11-01T09:00:00.000Z" });
+    ).toEqual({ kind: "command", text: "bun test \\", startedAt: "2026-11-01T09:00:00.000Z" });
     expect(currentActivity([item("file_change", "running", { fileName: "gateway/src/host.ts" })])?.text).toBe("host.ts");
   });