Add native Spacer backing (placeholder, no flex-grow yet)

Author: colemancda

Sources/AndroidSwiftUI/AndroidSpacer.swift

@@ -0,0 +1,30 @@
+//
+//  AndroidSpacer.swift
+//  AndroidSwiftUI
+//
+//  Created by Alsey Coleman Miller on 7/16/26.
+//
+
+import AndroidKit
+
+extension Spacer: AnyAndroidView {
+
+    // NOTE: does not yet flex-grow to fill remaining space in its parent stack (that would require
+    // AndroidRenderer's generic `addView` mounting to apply per-child LayoutParams, e.g. `layout_weight`,
+    // which it doesn't do today). Rendered as a minimal-size placeholder so layouts that include a
+    // `Spacer()` (e.g. List's internal row padding) still mount without crashing.
+    public func createAndroidView(_ context: AndroidContent.Context) -> AndroidView.View {
+        let view = AndroidView.View(context)
+        let length = Int32(minLength ?? 0)
+        view.setLayoutParams(ViewGroup.LayoutParams(length, length))
+        return view
+    }
+
+    public func updateAndroidView(_ view: AndroidView.View) {
+
+    }
+
+    public func removeAndroidView() {
+
+    }
+}