Initial commit: Learning Lab Express

Includes fixes found while reviewing the app:
- Results: open each result by a type+agent+id key, so a video and a
  material draft with the same id no longer open each other's popup
- AuthGate: clear the query cache during render, before pages build their
  queries, and remount pages on organization switch (pages no longer stay
  on skeletons for up to a minute after sign-in or refresh)
- Instruction: keep only failed rules after a partial approve, so retrying
  does not create the successful schedules twice; drop the monthly note
  once count or frequency is edited
- Parser/schedules: never schedule a count below one
- Audio: ignore the end event of a cancelled utterance when changing speed
- Downloads: revoke the object URL later so Safari/Firefox can read it
- Results: refetch SCORM content when any part's revision changes; show a
  failed video as failed instead of "still rendering"

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,34 @@
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import { defineConfig, loadEnv } from 'vite'
+import react from '@vitejs/plugin-react'
+
+// Clerk publishable keys are public. Default to the engine's own key so Express
+// and learning-lab share one Clerk instance (same users, organizations, credits).
+function engineClerkKey(): string {
+  try {
+    const env = readFileSync(fileURLToPath(new URL('../learning-lab/backend/.env', import.meta.url)), 'utf8')
+    return env.match(/^VITE_CLERK_PUBLISHABLE_KEY=["']?([^"'\s]+)/m)?.[1] ?? ''
+  } catch {
+    return ''
+  }
+}
+
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '')
+  const engineUrl = env.ENGINE_URL || 'http://localhost:8000'
+  const clerkKey = env.VITE_CLERK_PUBLISHABLE_KEY || engineClerkKey()
+  // Learning Studio (learning-lab/frontend), where a result opens in Compose for full editing.
+  const studioUrl = env.VITE_STUDIO_URL || 'http://localhost:5173'
+
+  return {
+    plugins: [react()],
+    define: {
+      'import.meta.env.VITE_CLERK_PUBLISHABLE_KEY': JSON.stringify(clerkKey),
+      'import.meta.env.VITE_STUDIO_URL': JSON.stringify(studioUrl),
+    },
+    // Same-origin /api keeps the engine free of CORS setup, as in production behind one domain.
+    server: { port: 5174, proxy: { '/api': { target: engineUrl, changeOrigin: true } } },
+    preview: { port: 5174, proxy: { '/api': { target: engineUrl, changeOrigin: true } } },
+  }
+})