CourseHub: AJAX video course player (PHP + MySQL + Bootstrap + Plyr)

Scans nested course folders for mp4s, tracks per-user resume position
and per-folder progress. SPA frontend with hash routing over a JSON API;
range-request streaming via stream.php.

api/scan.php

@@ -0,0 +1,20 @@
+<?php
+// POST api/scan.php -> rescan the library, returns stats.
+require_once __DIR__ . '/../includes/auth.php';
+require_once __DIR__ . '/../includes/functions.php';
+
+header('Content-Type: application/json');
+requireLoginApi();
+
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    http_response_code(405);
+    echo json_encode(['error' => 'Method not allowed']);
+    exit;
+}
+
+try {
+    echo json_encode(['ok' => true, 'stats' => scanLibrary()]);
+} catch (Throwable $e) {
+    http_response_code(500);
+    echo json_encode(['error' => $e->getMessage()]);
+}