refactor(userspace): split syscall/fat16/ext4 by concern; trim comments

crates/servers/storage-server/src/protocol.rs

@@ -1,10 +1,5 @@
-//! The storage protocol. A client first `Attach`es: the server makes it a
-//! buffer region and replies with a capability to it, which the client
-//! maps. Paths, file data and directory listings then travel through that
-//! buffer; the message words carry only lengths and handles, and the
-//! server clamps every length to the buffer. Clients are told apart by
-//! their endpoint badge, and a handle only works for the client that
-//! opened it.
+//! Storage protocol: a client `Attach`es to get a shared buffer; paths and
+//! data travel through it, message words carry only lengths and handles.
 
 use server_framework::{Decode, Encode};
 use crate::filesystem::FileHandle;