fix(ui): make chapter bridge manual-only and add release gate

Remove auto chapter-bridge prompt on book/chapter open so users trigger it from the cockpit. Fix AiPanel duplicate import that broke dev builds, and add release smoke tests plus test:release/test:ci scripts.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/release/build-artifacts.test.ts

@@ -0,0 +1,18 @@
+import { existsSync } from 'fs'
+import { join } from 'path'
+import { describe, it, expect } from 'vitest'
+
+const ROOT = join(import.meta.dirname, '../..')
+
+const REQUIRED_ARTIFACTS = [
+  'out/main/index.js',
+  'out/preload/index.js',
+  'out/renderer/index.html'
+]
+
+describe('release gate: build artifacts', () => {
+  it('UT-RELEASE-02: production build outputs exist', () => {
+    const missing = REQUIRED_ARTIFACTS.filter((rel) => !existsSync(join(ROOT, rel)))
+    expect(missing, `Run npm run build first. Missing: ${missing.join(', ')}`).toEqual([])
+  })
+})