feat: integrate MinIO for video storage, add video routes, and update README with API documentation

Backend/utils/minio.ts

@@ -0,0 +1,45 @@
+import { Client } from 'minio';
+
+const endpoint = process.env.MINIO_ENDPOINT ?? 'localhost';
+const port = Number(process.env.MINIO_PORT ?? 9000);
+const useSSL = (process.env.MINIO_USE_SSL ?? 'false').toLowerCase() === 'true';
+const accessKey = process.env.MINIO_ACCESS_KEY;
+const secretKey = process.env.MINIO_SECRET_KEY;
+
+if (!accessKey || !secretKey) {
+  throw new Error('MINIO_ACCESS_KEY and MINIO_SECRET_KEY must be set');
+}
+
+export const minioBucket = process.env.MINIO_BUCKET ?? 'videos';
+export const minioPresignedExpirySeconds = Number(process.env.MINIO_PRESIGNED_EXPIRY_SECONDS ?? 60 * 10);
+
+export const minioClient = new Client({
+  endPoint: endpoint,
+  port,
+  useSSL,
+  accessKey,
+  secretKey,
+});
+
+let ensureBucketPromise: Promise<void> | null = null;
+
+export const ensureMinioBucket = async (): Promise<void> => {
+  if (ensureBucketPromise) {
+    return ensureBucketPromise;
+  }
+
+  ensureBucketPromise = (async () => {
+    const exists = await minioClient.bucketExists(minioBucket);
+
+    if (!exists) {
+      await minioClient.makeBucket(minioBucket, process.env.MINIO_REGION ?? 'us-east-1');
+    }
+  })();
+
+  try {
+    await ensureBucketPromise;
+  } catch (error) {
+    ensureBucketPromise = null;
+    throw error;
+  }
+};