V0.8.27 group manager changes

backend/src/routes/messages.js

@@ -55,6 +55,17 @@ router.get('/group/:groupId', authMiddleware, (req, res) => {
   if (!group) return res.status(403).json({ error: 'Access denied' });
 
   const { before, limit = 50 } = req.query;
+
+  // For managed groups: find when this user joined so we can hide older messages
+  let joinedAt = null;
+  if (group.is_managed) {
+    const membership = db.prepare('SELECT joined_at FROM group_members WHERE group_id = ? AND user_id = ?').get(group.id, req.user.id);
+    if (membership?.joined_at) {
+      // Strip time — they can see messages from the start of the day they joined
+      joinedAt = membership.joined_at.slice(0, 10); // 'YYYY-MM-DD'
+    }
+  }
+
   let query = `
     SELECT m.*, 
       u.name as user_name, u.display_name as user_display_name, u.avatar as user_avatar, u.role as user_role, u.status as user_status, u.hide_admin_tag as user_hide_admin_tag, u.about_me as user_about_me, u.allow_dm as user_allow_dm,
@@ -69,6 +80,12 @@ router.get('/group/:groupId', authMiddleware, (req, res) => {
   `;
   const params = [req.params.groupId];
 
+  // Enforce join-date visibility for managed groups
+  if (joinedAt) {
+    query += ` AND date(m.created_at) >= ?`;
+    params.push(joinedAt);
+  }
+
   if (before) {
     query += ' AND m.id < ?';
     params.push(before);