feat(commerce): integrate RevenueCat entitlements and paywalls

Scripts/render-pro-paywall-icon.swift

@@ -0,0 +1,28 @@
+import AppKit
+import SwiftUI
+
+// Preserve the former native Pro hero in RevenueCat's remote image component.
+// Run from the repository root: swift Scripts/render-pro-paywall-icon.swift
+@MainActor
+func renderIcon(name: String, red: Double, green: Double, blue: Double) throws {
+    let content = Image(systemName: "sparkles.rectangle.stack.fill")
+        .font(.system(size: 52, weight: .medium))
+        .foregroundStyle(.tint)
+        .tint(Color(red: red, green: green, blue: blue))
+        .symbolRenderingMode(.hierarchical)
+        .frame(width: 80, height: 72)
+    let renderer = ImageRenderer(content: content)
+    renderer.scale = 4
+    guard let cgImage = renderer.cgImage,
+        let png = NSBitmapImageRep(cgImage: cgImage).representation(using: .png, properties: [:])
+    else { throw CocoaError(.fileWriteUnknown) }
+    let directory = URL(filePath: FileManager.default.currentDirectoryPath)
+        .appending(path: "Design/Brand/ProPaywall", directoryHint: .isDirectory)
+    try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
+    try png.write(to: directory.appending(path: name))
+}
+
+try MainActor.assumeIsolated {
+    try renderIcon(name: "pro-hero-light.png", red: 0, green: 122.0 / 255, blue: 1)
+    try renderIcon(name: "pro-hero-dark.png", red: 10.0 / 255, green: 132.0 / 255, blue: 1)
+}