drop stale send_file_dm doc refs (per review)

hive-matrix-mcp/src/handlers.rs

@@ -226,14 +226,14 @@ pub async fn send_dm(client: &Client, user_id: &str, body: &str) -> DaemonRespon
     }
 }
 
-/// Maximum file size accepted by `send_file` / `send_file_dm`.
+/// Maximum file size accepted by `send_file`.
 const MAX_UPLOAD_BYTES: u64 = 50 * 1024 * 1024;
 
 /// Read a local file and post it as a matrix attachment to `room`,
 /// inferring the MIME type from the file extension. An optional
 /// `caption` is sent as a best-effort follow-up text message (the
 /// attachment has already landed, so a caption failure is non-fatal).
-/// Shared by `send_file` and `send_file_dm`.
+/// Used by `send_file`.
 async fn upload_attachment(
     room: &matrix_sdk::Room,
     path: &str,