feat(desktop): add layout transition switch (#36667)

Co-authored-by: Brendan Allan <git@brendonovich.dev>

packages/desktop/src/main/install-state.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, test } from "bun:test"
+import { hasExistingAppState } from "./install-state"
+
+const file = (name: string) => ({ name, isDirectory: () => false })
+const directory = (name: string) => ({ name, isDirectory: () => true })
+
+describe("hasExistingAppState", () => {
+  test("ignores files Electron may create on a fresh install", () => {
+    expect(hasExistingAppState([])).toBe(false)
+    expect(hasExistingAppState([file("Local State"), directory("Crashpad")])).toBe(false)
+  })
+
+  test("recognizes state written by an earlier OpenCode launch", () => {
+    expect(hasExistingAppState([file("opencode.settings")])).toBe(true)
+    expect(hasExistingAppState([file("opencode.global.dat")])).toBe(true)
+    expect(hasExistingAppState([file("window-state-abc.json")])).toBe(true)
+    expect(hasExistingAppState([directory("opencode")])).toBe(true)
+  })
+})