fix(split-screen): allow layout creation without randomUUID (#1490)

* fix(split-screen): allow layout creation without randomUUID

* test(credentials): avoid flaky Ed25519 key generation

src/backend/tests/plugins/ctx-credentials.test.ts

@@ -328,7 +328,7 @@ describe("ctx.credentials.registerSecretResolver", () => {
 });
 
 describe("ctx.credentials.listSshKeys", () => {
-  const pair = ssh2.utils.generateKeyPairSync("ed25519");
+  const pair = ssh2.utils.generateKeyPairSync("rsa", { bits: 2048 });
   const derived = (() => {
     const parsed = ssh2.utils.parseKey(pair.private);
     const key = Array.isArray(parsed) ? parsed[0] : parsed;

src/ui/AppShell.tsx

@@ -1926,7 +1926,10 @@ export function AppShell({
     }
     const splitNumber =
       tabs.filter((tab) => tab.type === "split-screen").length + 1;
-    const instanceId = crypto.randomUUID();
+    const instanceId =
+      typeof crypto.randomUUID === "function"
+        ? crypto.randomUUID()
+        : `${Date.now().toString(36)}-${Math.random().toString(36).slice(2)}-${Math.random().toString(36).slice(2)}`;
     const id = `split-${instanceId}`;
     const sizes = defaultSizes(mode);
     const splitTab: Tab = {