fix(ui): detect VS Code from bootstrap config in shared runtime helpers

d2efa707 fixed projects-store detection via __VSCODE_CONFIG__, but
lib/desktop.isVSCodeRuntime (used by useDirectoryStore) still required
RuntimeAPIs. At webview startup that left directory init on stale
localStorage paths from other windows (#2359).

Share bootstrap detection in lib/vscodeBootstrap and use it from both
desktop runtime checks and the projects-store helper.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/lib/vscodeBootstrap.test.ts

@@ -0,0 +1,29 @@
+import { afterEach, describe, expect, test } from 'bun:test';
+import { getVSCodeBootstrapConfig, isVSCodeBootstrapPresent } from './vscodeBootstrap';
+
+describe('VS Code bootstrap config', () => {
+  afterEach(() => {
+    delete (globalThis as { window?: unknown }).window;
+  });
+
+  test('reads extension-host __VSCODE_CONFIG__ before RuntimeAPIs exist', () => {
+    (globalThis as { window: unknown }).window = {
+      __VSCODE_CONFIG__: {
+        workspaceFolder: '/workspace/project-one',
+        workspaceFolders: [{ name: 'project-one', path: '/workspace/project-one' }],
+      },
+    };
+
+    expect(getVSCodeBootstrapConfig()).toEqual({
+      workspaceFolder: '/workspace/project-one',
+      workspaceFolders: [{ name: 'project-one', path: '/workspace/project-one' }],
+    });
+    expect(isVSCodeBootstrapPresent()).toBe(true);
+  });
+
+  test('treats missing window/bootstrap as not VS Code', () => {
+    expect(getVSCodeBootstrapConfig()).toBeNull();
+    expect(isVSCodeBootstrapPresent()).toBe(false);
+    expect(isVSCodeBootstrapPresent(null)).toBe(false);
+  });
+});