test: crear registro de usuario para cumplir FK de user_preferences

Co-authored-by: aider (openrouter/openai/gpt-5) <aider@aider.chat>

tests/unit/services/reminders.gating.test.ts

@@ -25,6 +25,14 @@ describe('RemindersService - gating por grupos en modo enforce', () => {
     (ResponseQueue as any).add = async (msgs: any[]) => { sent.push(...msgs); };
     sent = [];
 
+    // Asegurar usuario receptor para satisfacer la FK de user_preferences
+    const iso = new Date().toISOString().replace('T', ' ').replace('Z', '');
+    memdb.exec(`
+      INSERT INTO users (id, first_seen, last_seen)
+      VALUES ('34600123456', '${iso}', '${iso}')
+      ON CONFLICT(id) DO NOTHING
+    `);
+
     // Preferencias del usuario receptor
     memdb.exec(`
       INSERT INTO user_preferences (user_id, reminder_freq, reminder_time, last_reminded_on, updated_at)