Fix social sync: update post_title and post_url on existing posts

Previously only INSERT included these fields, UPDATE ignored them.

Chronicler #76

services/arbiter-3.0/src/routes/api.js

@@ -78,6 +78,18 @@ router.post('/social/sync', async (req, res) => {
             const updateValues = [];
             let paramIndex = 1;
             
+            // Update title and URL if provided
+            if (post_title) {
+                updateFields.push(`post_title = $${paramIndex}`);
+                updateValues.push(post_title);
+                paramIndex++;
+            }
+            if (post_url) {
+                updateFields.push(`post_url = $${paramIndex}`);
+                updateValues.push(post_url);
+                paramIndex++;
+            }
+            
             // Build dynamic update based on provided metrics
             if (metrics) {
                 const metricFields = [