Fix portrait controller visibility and add per-button action toggles with undo

- Portrait gameplay: switch from VStack split to ZStack overlay so the game
  fills the screen and the virtual controller is bottom-aligned without an
  opaque dark background panel for built-in skins.
- VirtualControllerView: remove Color(white: 0.10) fallback in portraitLayout
  and replace single action-pad visibility with independent per-button checks
  for triangle, cross, square, and circle.
- PadLayoutStore: add per-button visibility fallback (explicit key wins, then
  group fallback). Save/load per-button visibility for action buttons in a
  separate INI namespace with -1 sentinel for absent keys.
- PadLayoutEditView: add ephemeral undo stack for in-progress edits. Cancel
  restores the original snapshot. Save clears undo state and persists.
- Editor visibility row: split the combined ACTION toggle into four separate
  toggles with user-facing labels: Toggle: X, Toggle: O, Toggle: Triangle,
  Toggle: Square.

Author: J1coding

app/src/main/swift/Models/PadLayoutStore.swift

@@ -47,8 +47,9 @@ enum VirtualPadButtonOffset {
 final class PadLayoutStore: @unchecked Sendable {
     static let shared = PadLayoutStore()
 
-    static let groupIDs = ["dpad", "action", "l1", "l2", "r1", "r2", "lstick", "rstick", "select", "start"]
+    static let actionButtonIDs = ["cross", "circle", "square", "triangle"]
     static let perButtonIDs = ["triangle", "circle", "square", "cross", "up", "down", "left", "right"]
+    static let groupIDs = ["dpad", "action", "l1", "l2", "r1", "r2", "lstick", "rstick", "select", "start"]
 
     var portrait: [String: PadGroupPosition] = [:]
     var landscape: [String: PadGroupPosition] = [:]
@@ -140,10 +141,15 @@ final class PadLayoutStore: @unchecked Sendable {
 
     // MARK: - Visibility helpers
 
-    /// Returns whether a control group is visible. Default is `true` (visible).
-    /// Visibility is stored globally (applies to both portrait and landscape).
+    /// Returns whether a control or button is visible.
+    /// If an explicit per-button key exists, it wins.
+    /// Otherwise, fall back to the group visibility (default: visible).
     func isControlVisible(_ id: String) -> Bool {
-        controlVisibility[id] ?? true
+        if let explicit = controlVisibility[id] {
+            return explicit
+        }
+        let group = groupID(for: id)
+        return controlVisibility[group] ?? true
     }
 
     func setControlVisible(_ id: String, visible: Bool) {
@@ -192,6 +198,14 @@ final class PadLayoutStore: @unchecked Sendable {
             let isVisible = isControlVisible(id)
             ARMSX2Bridge.setINIFloat("ARMSX2iOS/PadLayout/ControlVisibility", key: id, value: isVisible ? 1.0 : 0.0)
         }
+        // Per-button visibility overrides (only action buttons in this pass).
+        for id in Self.actionButtonIDs {
+            if let explicit = controlVisibility[id] {
+                ARMSX2Bridge.setINIFloat("ARMSX2iOS/PadLayout/ControlVisibility", key: id, value: explicit ? 1.0 : 0.0)
+            } else {
+                ARMSX2Bridge.setINIFloat("ARMSX2iOS/PadLayout/ControlVisibility", key: id, value: -1.0)
+            }
+        }
     }
 
     func load() {
@@ -266,6 +280,13 @@ final class PadLayoutStore: @unchecked Sendable {
                 controlVisibility[id] = (value > 0.5)
             }
         }
+        // Per-button visibility overrides.
+        for id in Self.actionButtonIDs {
+            let value = ARMSX2Bridge.getINIFloat("ARMSX2iOS/PadLayout/ControlVisibility", key: id, defaultValue: -1)
+            if value >= 0 {
+                controlVisibility[id] = (value > 0.5)
+            }
+        }
     }
 
     func resetPortrait() {

app/src/main/swift/Views/GameScreenView.swift

@@ -86,21 +86,15 @@ struct GameScreenView: View {
                     }
                     .ignoresSafeArea()
                 } else {
-                    // Portrait: split layout. Full-phone skins are skipped until viewport metadata is parsed.
+                    // Portrait: full-screen game with controller overlay at bottom.
                     ZStack {
-                        VStack(spacing: 0) {
-                            MetalGameView()
+                        MetalGameView()
+                        if effectiveVirtualPadVisible {
+                            VirtualControllerView()
                                 .frame(height: geo.size.height / 2)
-                            if effectiveVirtualPadVisible {
-                                VirtualControllerView()
-                                    .frame(height: geo.size.height / 2)
-                            } else {
-                                Spacer()
-                            }
-                        }
-                        .overlay(alignment: .topTrailing) {
-                            menuButtonOverlay(isLandscape: false)
+                                .frame(maxHeight: .infinity, alignment: .bottom)
                         }
+                        menuButtonOverlay(isLandscape: false)
                     }
                 }
             }