fix: UAT test — ESM compat, correct status codes, idempotent source setup

- Use import.meta.url for ESM-compatible __dirname
- Source creation expects 201, not 200
- Clean up existing sources before adding to avoid unique constraint violation
- Fix E2E docker-compose build context to project root

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

e2e/docker-compose.test.yml

@@ -1,8 +1,8 @@
 services:
   app:
     build:
-      context: ../backend
-      dockerfile: Dockerfile
+      context: ..
+      dockerfile: backend/Dockerfile
     container_name: ai-synth-test
     restart: "no"
     environment:

e2e/tests/generation-live.spec.ts

@@ -12,9 +12,12 @@ import { test, expect } from '@playwright/test';
 import type { Page } from '@playwright/test';
 import * as dotenv from 'dotenv';
 import * as path from 'path';
+import { fileURLToPath } from 'url';
 import { loginAsUser } from '../helpers/auth';
 
-// Load .env.test from the e2e directory
+// Load .env.test from the e2e directory (ESM-compatible __dirname)
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
 dotenv.config({ path: path.resolve(__dirname, '..', '.env.test') });
 
 const OPENAI_KEY = process.env.OPENAI_TEST_API_KEY;
@@ -120,10 +123,11 @@ test.describe('Live generation with OpenAI', () => {
   }) => {
     test.setTimeout(180_000);
 
-    // Navigate to app first (required for cookie domain), then login
+    // Set session cookie, then navigate to a stable page
     // OpenAI provider is already enabled from the migration seed data
-    await page.goto('/');
     await loginAsUser(page);
+    await page.goto('/');
+    await page.waitForLoadState('networkidle');
 
     // Step 2: Configure settings
     const settingsResp = await apiCall(page, 'PUT', '/api/v1/settings', {
@@ -145,12 +149,19 @@ test.describe('Live generation with OpenAI', () => {
     });
     expect(keyResp.status).toBe(200);
 
-    // Step 4: Add a source
+    // Step 4: Clean up existing sources, then add a fresh one
+    const existingSources = await apiCall(page, 'GET', '/api/v1/sources');
+    if (existingSources.data && Array.isArray(existingSources.data)) {
+      for (const source of existingSources.data) {
+        await apiCall(page, 'DELETE', `/api/v1/sources/${source.id}`);
+      }
+    }
+
     const sourceResp = await apiCall(page, 'POST', '/api/v1/sources', {
       title: 'OpenAI Blog',
       url: 'https://openai.com/blog',
     });
-    expect(sourceResp.status).toBe(200);
+    expect(sourceResp.status).toBe(201);
 
     // Step 5: Trigger generation
     const genResp = await apiCall(