feat(banks): bindable multi-bank action family — create/rename/delete/evacuate/activate/move/copy + full-height toggles (B3)

src/bank_panel.cpp

@@ -194,6 +194,13 @@ struct PanelState {
     // persistence is a noted follow-on. Mutated ONLY by a click in the footer strip.
     TailSetting tail;
 
+    // --- Vertical-split full-height layout (Phase B3) -------------------------
+    // Which region(s) the vertical split shows: both (Split, default), pool only,
+    // or named-banks only. B3 actions flip it (bankPanelToggled*FullHeight); B4's
+    // panel renders from it. In-memory only (a UI-layout preference, not project
+    // state — it must not travel with the .rpp); resets to Split on unload.
+    BankPanelFullHeight fullHeight = BankPanelFullHeight::Split;
+
     // --- Audition preview (Wave B) --------------------------------------------
     //
     // The stock preview register we hand to PlayPreview/StopPreview. Its cs/mutex
@@ -999,6 +1006,30 @@ TailSetting bankPanelTailSetting() {
     return s;
 }
 
+BankPanelFullHeight bankPanelFullHeight() {
+    // In-memory for the extension's lifetime (g_panel is static), like the tail
+    // setting: survives panel open/close and bank changes, resets to Split on unload.
+    return g_panel.fullHeight;
+}
+
+// Shared toggle body: enter `target` from any other state, or fall back to Split when
+// already at `target` (a second press restores the split). Requests a repaint via the
+// same InvalidateRect the refresh path uses, so an open panel reflects the change; a
+// closed panel (hwnd null) simply stores the bit for B4 to render when it opens.
+static void setFullHeight(BankPanelFullHeight target) {
+    g_panel.fullHeight =
+        (g_panel.fullHeight == target) ? BankPanelFullHeight::Split : target;
+    if (g_panel.hwnd) InvalidateRect(g_panel.hwnd, nullptr, FALSE);
+}
+
+void bankPanelToggledPoolFullHeight() {
+    setFullHeight(BankPanelFullHeight::PoolOnly);
+}
+
+void bankPanelToggledBanksFullHeight() {
+    setFullHeight(BankPanelFullHeight::BanksOnly);
+}
+
 void bankPanelShutdown() {
     closePanel();              // stops audition + destroys the window
     deinitPreview();           // destroy the preview lock (after the last stop)