fix: Auto-slot macros + heatmap auto-load on toggle

- Macro slot auto-assigned from macros.len() (no manual slot selection)
- Heatmap toggle auto-loads KEYSTATS? from firmware
- Debug logs for macro save/refresh

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/main.rs

@@ -489,6 +489,23 @@ fn main() {
         });
     }
 
+    // --- Heatmap toggle: auto-load data ---
+    {
+        let serial = serial.clone();
+        let tx = bg_tx.clone();
+
+        keymap_bridge.on_toggle_heatmap(move || {
+            let serial = serial.clone();
+            let tx = tx.clone();
+            std::thread::spawn(move || {
+                let mut ser = serial.lock().unwrap_or_else(|e| e.into_inner());
+                let lines = ser.query_command("KEYSTATS?").unwrap_or_default();
+                let (data, max) = logic::parsers::parse_heatmap_lines(&lines);
+                let _ = tx.send(BgMsg::HeatmapData(data, max));
+            });
+        });
+    }
+
     // --- Connect/Disconnect callbacks ---
     {
         let serial_c = serial.clone();
@@ -1203,7 +1220,7 @@ fn main() {
         window.global::<MacroBridge>().on_save_macro(move || {
             let Some(w) = window_weak.upgrade() else { return };
             let mb = w.global::<MacroBridge>();
-            let slot_num = mb.get_new_slot_idx() as u8;
+            let slot_num = mb.get_macros().row_count() as u8;
             let name = mb.get_new_name().to_string();
             let steps = macro_steps.borrow();
             let steps_str: Vec<String> = steps.iter().map(|&(kc, md)| {
@@ -1213,6 +1230,7 @@ fn main() {
             let steps_text = steps_str.join(",");
             drop(steps);
             let cmd = logic::protocol::cmd_macroseq(slot_num, &name, &steps_text);
+            eprintln!("MACRO SAVE: {}", cmd);
             let serial = serial.clone();
             let tx = tx.clone();
             std::thread::spawn(move || {
@@ -1606,6 +1624,7 @@ fn main() {
                                     window.global::<AdvancedBridge>().set_bt_status(SharedString::from(bt_text));
                                 }
                                 "macros" => {
+                                    eprintln!("MACRO raw lines: {:?}", lines);
                                     let macro_data = logic::parsers::parse_macro_lines(&lines);
                                     let model: Vec<MacroData> = macro_data.iter().map(|m| {
                                         let steps_str: Vec<String> = m.steps.iter().map(|s| {

ui/globals.slint

@@ -62,7 +62,8 @@ export global KeymapBridge {
     in-out property <string> selector-target: "keymap";
     callback select-key(int);
     callback switch-layer(int);
-    callback change-key(int, int); // key-index, new-keycode
+    callback change-key(int, int);
+    callback toggle-heatmap();
     callback rename-layer(int, string); // layer-index, new-name
 }
 

ui/tabs/tab_keymap.slint

@@ -106,7 +106,10 @@ export component TabKeymap inherits VerticalLayout {
                 }
 
                 TouchArea {
-                    clicked => { KeymapBridge.heatmap-enabled = !KeymapBridge.heatmap-enabled; }
+                    clicked => {
+                                KeymapBridge.heatmap-enabled = !KeymapBridge.heatmap-enabled;
+                                if KeymapBridge.heatmap-enabled { KeymapBridge.toggle-heatmap(); }
+                            }
                     mouse-cursor: pointer;
                 }
             }

ui/tabs/tab_macros.slint

@@ -39,12 +39,6 @@ export component TabMacros inherits Rectangle {
                     spacing: 8px;
                     alignment: start;
 
-                    Text { text: "Slot:"; color: Theme.fg-secondary; font-size: 12px; vertical-alignment: center; }
-                    DarkComboBox {
-                        width: 60px;
-                        model: ["0","1","2","3","4","5","6","7","8","9"];
-                        current-index <=> MacroBridge.new-slot-idx;
-                    }
                     Text { text: "Name:"; color: Theme.fg-secondary; font-size: 12px; vertical-alignment: center; }
                     DarkLineEdit {
                         horizontal-stretch: 1;