feat: comment pagination, Matrix integration, Synapse mention resolution

Comment pagination:
- CommentModel: add getCommentCount(), paginated getCommentsByTicketId()
  with getThreadedCommentsPaged() for threading + LIMIT/OFFSET
- TicketController: load first 50 root comments + total count on page load
- api/get_comments.php: new AJAX endpoint for Load More (index.php routed)
- TicketView: Load More button + buildCommentEl() JS renderer for AJAX comments;
  passes totalComments/commentOffset/isAdmin to window.ticketData

Matrix integration:
- NotificationHelper: add sendStatusChangeNotification(), sendCommentNotification(),
  sendMentionNotification(), sendAssignmentNotification() alongside existing
  sendTicketNotification(); internal fire() helper replaces duplicated cURL logic
- SynapseHelper: new helper that resolves SSO usernames → Matrix IDs by querying
  Synapse Admin REST API directly (no caching, no stale data)
- config.php: add SYNAPSE_ADMIN_URL, SYNAPSE_ADMIN_TOKEN, MATRIX_NOTIFY_COMMENTS,
  MATRIX_NOTIFY_ASSIGNMENTS config keys (all from .env)
- api/update_ticket.php: fire status-change notification after successful save
- api/add_comment.php: resolve @mentioned usernames via SynapseHelper and fire
  mention notification; fire general comment notification when MATRIX_NOTIFY_COMMENTS=1
- api/assign_ticket.php: fire assignment notification (resolves assignee via Synapse)
  when MATRIX_NOTIFY_ASSIGNMENTS=1

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/add_comment.php

@@ -29,6 +29,8 @@ try {
     require_once $auditLogModelPath;
     require_once dirname(__DIR__) . '/helpers/Database.php';
     require_once dirname(__DIR__) . '/models/TicketModel.php';
+    require_once dirname(__DIR__) . '/helpers/NotificationHelper.php';
+    require_once dirname(__DIR__) . '/helpers/SynapseHelper.php';
 
     // Check authentication via session
     if (session_status() === PHP_SESSION_NONE) {
@@ -123,6 +125,25 @@ try {
             );
         }
 
+        // Matrix notifications
+        $authorDisplay = $currentUser['display_name'] ?? $currentUser['username'] ?? null;
+        $commentText   = $data['comment_text'] ?? '';
+        $ticketTitle   = $ticket['title'] ?? "Ticket #{$ticketId}";
+
+        // @mention notifications — resolve usernames → Matrix IDs via Synapse Admin API
+        if (!empty($mentionedUsers)) {
+            $mentionedUsernames = array_column($mentionedUsers, 'username');
+            $mentionedMatrixIds = SynapseHelper::resolveUsernames($mentionedUsernames);
+            if (!empty($mentionedMatrixIds)) {
+                NotificationHelper::sendMentionNotification($ticketId, $ticketTitle, $commentText, $authorDisplay, $mentionedMatrixIds);
+            }
+        }
+
+        // General comment notification (opt-in via MATRIX_NOTIFY_COMMENTS)
+        if (!empty($GLOBALS['config']['MATRIX_NOTIFY_COMMENTS'])) {
+            NotificationHelper::sendCommentNotification($ticketId, $ticketTitle, $commentText, $authorDisplay);
+        }
+
         // Add mentioned users to result for frontend
         $result['mentions'] = array_map(function($u) {
             return $u['username'];

api/assign_ticket.php

@@ -3,6 +3,8 @@ require_once __DIR__ . '/bootstrap.php';
 require_once dirname(__DIR__) . '/models/TicketModel.php';
 require_once dirname(__DIR__) . '/models/AuditLogModel.php';
 require_once dirname(__DIR__) . '/models/UserModel.php';
+require_once dirname(__DIR__) . '/helpers/NotificationHelper.php';
+require_once dirname(__DIR__) . '/helpers/SynapseHelper.php';
 
 // Get request data
 $data = json_decode(file_get_contents('php://input'), true);
@@ -60,6 +62,21 @@ if ($assignedTo === null || $assignedTo === '') {
     $success = $ticketModel->assignTicket($ticketId, $assignedTo, $userId);
     if ($success) {
         $auditLogModel->log($userId, 'assign', 'ticket', $ticketId, ['assigned_to' => $assignedTo]);
+
+        if (!empty($GLOBALS['config']['MATRIX_NOTIFY_ASSIGNMENTS'])) {
+            $changedByDisplay = $currentUser['display_name'] ?? $currentUser['username'] ?? null;
+            $assigneeName     = $targetUser['display_name'] ?? $targetUser['username'] ?? null;
+            $assigneeMatrix   = isset($targetUser['username'])
+                                ? SynapseHelper::resolveUsername($targetUser['username'])
+                                : null;
+            NotificationHelper::sendAssignmentNotification(
+                $ticketId,
+                $ticket['title'] ?? "Ticket #{$ticketId}",
+                $assigneeName,
+                $assigneeMatrix,
+                $changedByDisplay
+            );
+        }
     }
 }
 

api/get_comments.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * Get Comments API
+ * Returns paginated comments for a ticket (used by "Load more" on ticket view)
+ */
+
+require_once __DIR__ . '/bootstrap.php';
+require_once dirname(__DIR__) . '/models/CommentModel.php';
+require_once dirname(__DIR__) . '/models/TicketModel.php';
+
+if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
+    http_response_code(405);
+    echo json_encode(['success' => false, 'error' => 'Method not allowed']);
+    exit;
+}
+
+$ticketId = isset($_GET['ticket_id']) ? (int)$_GET['ticket_id'] : 0;
+$offset   = isset($_GET['offset'])    ? max(0, (int)$_GET['offset'])   : 0;
+$limit    = isset($_GET['limit'])     ? min(100, max(1, (int)$_GET['limit'])) : 50;
+
+if ($ticketId <= 0) {
+    http_response_code(400);
+    echo json_encode(['success' => false, 'error' => 'Invalid ticket_id']);
+    exit;
+}
+
+$ticketModel = new TicketModel($conn);
+$ticket = $ticketModel->getTicketById($ticketId);
+if (!$ticket || !$ticketModel->canUserAccessTicket($ticket, $currentUser)) {
+    http_response_code(404);
+    echo json_encode(['success' => false, 'error' => 'Ticket not found']);
+    exit;
+}
+
+$commentModel  = new CommentModel($conn);
+$total         = $commentModel->getCommentCount($ticketId);
+$comments      = $commentModel->getCommentsByTicketId($ticketId, true, $limit, $offset);
+
+echo json_encode([
+    'success'  => true,
+    'comments' => $comments,
+    'total'    => $total,
+    'offset'   => $offset,
+    'limit'    => $limit,
+    'has_more' => ($offset + $limit) < $total,
+]);

api/update_ticket.php

@@ -26,6 +26,7 @@ try {
     require_once $commentModelPath;
     require_once $auditLogModelPath;
     require_once $workflowModelPath;
+    require_once dirname(__DIR__) . '/helpers/NotificationHelper.php';
 
     // Check authentication via session
     if (session_status() === PHP_SESSION_NONE) {
@@ -207,6 +208,18 @@ try {
                 }
             }
 
+            // Notify on status change
+            if ($currentTicket['status'] !== $updateData['status']) {
+                $changedBy = $this->currentUser['display_name'] ?? $this->currentUser['username'] ?? null;
+                NotificationHelper::sendStatusChangeNotification(
+                    $id,
+                    $currentTicket['status'],
+                    $updateData['status'],
+                    $updateData['title'],
+                    $changedBy
+                );
+            }
+
             return [
                 'success'    => true,
                 'status'     => $updateData['status'],