Fix SMB negotiate: cipher_count=1 and username case sensitivity

vendor/smb-server/src/builder.rs

@@ -75,9 +75,10 @@ impl Share {
     }
 
     /// Grant `access` to the given (already-registered) user. Multiple calls
-    /// accumulate.
+    /// accumulate. Username is normalized to lowercase for SMB case-insensitive
+    /// matching.
     pub fn user(mut self, name: impl Into<String>, access: Access) -> Self {
-        self.users.insert(name.into(), access);
+        self.users.insert(name.into().to_lowercase(), access);
         self
     }
 
@@ -163,7 +164,7 @@ impl SmbServerBuilder {
     }
 
     pub fn user(mut self, name: impl Into<String>, password: impl Into<String>) -> Self {
-        let n = name.into();
+        let n = name.into().to_lowercase();
         if !self.users.contains_key(&n) {
             self.user_order.push(n.clone());
         }