refactor(backend): simplify media schema and recording metadata

Backend/docs/openapi.ts

@@ -32,6 +32,8 @@ const VideoUploadUrlRequestSchema = registry.register(
     fileName: z.string().min(1).max(255),
     deviceId: z.string().uuid(),
     prefix: z.string().optional(),
+    recordingId: z.string().uuid().optional(),
+    eventId: z.string().uuid().optional(),
   }),
 );
 
@@ -178,7 +180,7 @@ registry.registerPath({
 registry.registerPath({
   method: 'post',
   path: '/videos/upload-url',
-  summary: 'Create a presigned upload URL',
+  summary: 'Create a presigned upload URL and attach it to a recording',
   tags: ['Videos'],
   security: [{ cookieAuth: [] }],
   request: {