some build changes

Femto.Database/Program.cs

@@ -25,6 +25,8 @@ var connectionStringArg = new Argument<string>(
 
 var connectionStringOption = new Option<string?>(
     ["-c", "--connection-string"],
+    
+    // we default this to the same variable used by the server application
     () => System.Environment.GetEnvironmentVariable("ConnectionStrings__Database") ?? null,
     "the connection string to the database"
 );