Make mobile terminals load faster (#1147)

* Speed up terminal restores on mobile

* Preserve terminal output bytes in the app

packages/app/src/terminal/runtime/terminal-restore-options.test.ts

@@ -0,0 +1,39 @@
+import { describe, expect, it } from "vitest";
+
+import { resolveTerminalRestoreOptions } from "./terminal-restore-options";
+
+describe("terminal restore options", () => {
+  it("omits restore options for daemons without terminal restore modes", () => {
+    expect(
+      resolveTerminalRestoreOptions({
+        supportsTerminalRestoreModes: false,
+        size: { rows: 24, cols: 80 },
+      }),
+    ).toBeUndefined();
+  });
+
+  it("requests visible snapshot restore with bounded scrollback for capable daemons", () => {
+    expect(
+      resolveTerminalRestoreOptions({
+        supportsTerminalRestoreModes: true,
+        size: { rows: 24, cols: 80 },
+      }),
+    ).toEqual({
+      mode: "visible-snapshot",
+      scrollbackLines: 200,
+      size: { rows: 24, cols: 80 },
+    });
+  });
+
+  it("omits size until the terminal has been measured", () => {
+    expect(
+      resolveTerminalRestoreOptions({
+        supportsTerminalRestoreModes: true,
+        size: null,
+      }),
+    ).toEqual({
+      mode: "visible-snapshot",
+      scrollbackLines: 200,
+    });
+  });
+});