feat: restrict DTR/RTS to serial transport; allow manual port input; clean up tool binaries

- Only show DTR/RTS toggles when transport is Serial (not TCP/UDP)
- Add manual port text entry next to serial port combo box
- Reduce combo box width to 180px to make room for text input
- Remove compiled ELF binaries from tools/ and add to .gitignore

.gitignore

@@ -1 +1,5 @@
 /target
+
+# Compiled binaries in tools/
+tools/test_plot_c
+tools/test_text_c

crates/xserial-gui/src/app.rs

@@ -928,7 +928,9 @@ fn render_session_controls(
                 tab.status = ConnectionStatus::Error(String::from("session not found"));
             }
         }
-        if matches!(tab.status, ConnectionStatus::Connected) {
+        if matches!(tab.status, ConnectionStatus::Connected)
+            && matches!(tab.session_config.transport, TransportConfig::Serial { .. })
+        {
             let dtr_changed = ui.checkbox(&mut tab.dtr, "DTR").changed();
             let rts_changed = ui.checkbox(&mut tab.rts, "RTS").changed();
             if dtr_changed || rts_changed {
@@ -936,8 +938,12 @@ fn render_session_controls(
                     let dtr = tab.dtr;
                     let rts = tab.rts;
                     tokio::spawn(async move {
-                        if dtr_changed { let _ = handle.set_dtr(dtr).await; }
-                        if rts_changed { let _ = handle.set_rts(rts).await; }
+                        if dtr_changed {
+                            let _ = handle.set_dtr(dtr).await;
+                        }
+                        if rts_changed {
+                            let _ = handle.set_rts(rts).await;
+                        }
                     });
                 } else {
                     tab.status = ConnectionStatus::Error(String::from("session not found"));

crates/xserial-gui/src/panels/config.rs

@@ -547,7 +547,7 @@ fn render_serial_port_combo(ui: &mut Ui, form: &mut ConfigForm) {
     ui.horizontal(|ui| {
         ui.label("Port:");
         ComboBox::from_id_salt("serial_port")
-            .width(220.0)
+            .width(180.0)
             .selected_text(selected_text)
             .show_ui(ui, |ui| {
                 if available_ports.is_empty() {
@@ -570,6 +570,7 @@ fn render_serial_port_combo(ui: &mut Ui, form: &mut ConfigForm) {
                     );
                 }
             });
+        ui.add(TextEdit::singleline(&mut form.port).desired_width(260.0));
     });
 }