Add friends' birthdays feature: Implement API endpoint to retrieve friends' birthdays for a specified year, enhance calendar service to handle visibility checks, and update CalendarView to display birthday events with distinct styling. This update improves user experience by allowing users to view important dates of their friends.

backend/controllers/calendarController.js

@@ -119,5 +119,26 @@ export default {
             }
             res.status(500).json({ error: error.message || 'Internal server error' });
         }
+    },
+
+    /**
+     * GET /api/calendar/birthdays
+     * Get friends' birthdays for a given year
+     * Query params: year (required)
+     */
+    async getFriendsBirthdays(req, res) {
+        const hashedUserId = getHashedUserId(req);
+        if (!hashedUserId) {
+            return res.status(401).json({ error: 'Unauthorized' });
+        }
+
+        try {
+            const year = parseInt(req.query.year) || new Date().getFullYear();
+            const birthdays = await calendarService.getFriendsBirthdays(hashedUserId, year);
+            res.json(birthdays);
+        } catch (error) {
+            console.error('Calendar getFriendsBirthdays:', error);
+            res.status(500).json({ error: error.message || 'Internal server error' });
+        }
     }
 };