fix: use broader theme and 30-day window in generation E2E test

'AI Weekly' with 7 days was too narrow — most articles filtered as
too old. 'Intelligence Artificielle' with 30 days gives more results.

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

e2e/tests/generation-live.spec.ts

@@ -132,8 +132,8 @@ test.describe('Live generation with OpenAI', () => {
 
     // Step 2: Configure settings
     const settingsResp = await apiCall(page, 'PUT', '/api/v1/settings', {
-      theme: 'AI Weekly',
-      max_age_days: 7,
+      theme: 'Intelligence Artificielle',
+      max_age_days: 30,
       categories: ['AI News'],
       max_items_per_category: 4,
       max_articles_per_source: 3,