Get rid of Signature model and change sign and verify to sign_detatched and verify_detached

spec/cox_spec.cr

@@ -29,10 +29,10 @@ describe Cox do
     signing_pair = Cox::SignKeyPair.new
 
     # Create signature using the secret key
-    signature = Cox.sign(message, signing_pair.secret)
+    signature = Cox.sign_detached(message, signing_pair.secret)
 
     # Verify the signature on the message
-    verified = Cox.verify(signature, message, signing_pair.public)
+    verified = Cox.verify_detached(signature, message, signing_pair.public)
 
     verified.should eq(true)
   end

src/cox.cr

@@ -23,7 +23,7 @@ module Cox
     output_buffer
   end
 
-  def self.sign(message, secret_key : SignSecretKey)
+  def self.sign_detached(message, secret_key : SignSecretKey)
     message_buffer = message.to_slice
     message_buffer_size = message_buffer.bytesize
     signature_output_buffer = Bytes.new(LibSodium::SIGNATURE_BYTES)
@@ -32,7 +32,7 @@ module Cox
     signature_output_buffer
   end
 
-  def self.verify(signature, message, public_key : SignPublicKey)
+  def self.verify_detached(signature, message, public_key : SignPublicKey)
     signature_buffer = signature.to_slice
     message_buffer = message.to_slice
     message_buffer_size = message_buffer.bytesize

src/cox/signature.cr

@@ -1,15 +0,0 @@
-require "./lib_sodium"
-
-module Cox
-  class Signature
-    property bytes : Bytes
-
-    KEY_LENGTH = LibSodium::SIGNATURE_BYTES
-
-    def initialize(@bytes : Bytes)
-      if bytes.bytesize != KEY_LENGTH
-        raise ArgumentError.new("Signature must be #{KEY_LENGTH} bytes, got #{bytes.bytesize}")
-      end
-    end
-  end
-end