Move finalize into bind_key, remove finalize trait method

Send the finalize packet [03 FD FE FF] after each bind_key call
(matching yawor's PR kriomant#154 approach) instead of adding a new trait
method. This keeps the Keyboard trait unchanged from upstream.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: skarard

src/keyboard/k8850.rs

@@ -122,12 +122,10 @@ impl Keyboard for Keyboard8850 {
 
         send_message(output, &msg);
 
-        Ok(())
-    }
-
-    fn finalize(&self, output: &mut Vec<u8>) {
-        // The 8850 requires a finalize packet after all key bindings are written.
+        // The 8850 requires a finalize packet after each key binding.
         send_message(output, &[0x03, 0xFD, 0xFE, 0xFF]);
+
+        Ok(())
     }
 
     fn set_led(&mut self, _args: &[String], _output: &mut Vec<u8>) -> Result<()> {
@@ -298,13 +296,19 @@ mod tests {
     }
 
     #[test]
-    fn test_finalize() {
+    fn test_bind_key_includes_finalize() {
+        // Every bind_key call should append a finalize packet [03 FD FE FF]
         let kb = Keyboard8850::new(16, 3).unwrap();
         let mut output = Vec::new();
-        kb.finalize(&mut output);
+        let macro_ = Macro::Keyboard(KeyboardEvent(
+            Default::default(),
+            vec![Accord { modifiers: EnumSet::empty(), code: Some(Code::WellKnown(WellKnownCode::A)) }],
+        ));
+        kb.bind_key(0, Key::Button(0), &macro_, &mut output).unwrap();
 
-        assert_eq!(output.len(), 64);
-        assert_msg(&output, 0, &[0x03, 0xFD, 0xFE, 0xFF]);
+        // Should be 2 messages: the key binding + the finalize
+        assert_eq!(output.len(), 2 * 64);
+        assert_msg(&output, 1, &[0x03, 0xFD, 0xFE, 0xFF]);
     }
 
 }

src/keyboard/mod.rs

@@ -17,9 +17,6 @@ use itertools::Itertools as _;
 pub trait Keyboard {
     fn bind_key(&self, layer: u8, key: Key, expansion: &Macro, output: &mut Vec<u8>) -> Result<()>;
     fn set_led(&mut self, args: &[String], output: &mut Vec<u8>) -> Result<()>;
-    /// Called after all bind_key calls to finalize/commit the config.
-    /// Default implementation does nothing (k884x handles this inline).
-    fn finalize(&self, _output: &mut Vec<u8>) {}
 
     fn preferred_endpoint() -> u8 where Self: Sized;
 }

src/main.rs

@@ -102,9 +102,6 @@ fn main() -> Result<()> {
                 }
             }
 
-            // Finalize (device-specific commit sequence)
-            keyboard.finalize(&mut output);
-
             // Send all accumulated data to device
             send_to_device(&handle, endpoint, &output)?;
         }