feat(ios): [IAP] Paywall Initial Commit (#13609)

Requires https://github.com/toeverything/AFFiNE/pull/13606 to be merged.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- New Features
- Introduced an in-app Paywall with Pro, AI, and Believer plans, feature
previews, paging dots, and selectable pricing options.
- Added purchase and restore actions, plus a unified, polished UI using
new color/icon resources.

- Documentation
  - Added Swift Code Style Guidelines.

- Chores
- Updated dependencies (including MarkdownView 3.4.2), added new
resource packages, and removed an unused dependency.
  - Raised iOS deployment target to 16.5 and refreshed project settings.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: DarkSky <25152247+darkskygit@users.noreply.github.com>

packages/frontend/apps/ios/App/App/AffineViewController.swift

@@ -32,8 +32,8 @@ class AFFiNEViewController: CAPBridgeViewController {
       CookiePlugin(),
       HashcashPlugin(),
       NavigationGesturePlugin(),
-      // IntelligentsPlugin(representController: self), // no longer put in use
       NbStorePlugin(),
+      PayWallPlugin(associatedController: self),
     ]
     plugins.forEach { bridge?.registerPluginInstance($0) }
   }

packages/frontend/apps/ios/App/App/Plugins/PayWall/PayWallPlugin.swift

@@ -1,8 +1,18 @@
+import AffinePaywall
 import Capacitor
 import Foundation
+import SwiftUI
+import UIKit
 
 @objc(PayWallPlugin)
 public class PayWallPlugin: CAPPlugin, CAPBridgedPlugin {
+  init(associatedController: UIViewController? = nil) {
+    controller = associatedController
+    super.init()
+  }
+
+  weak var controller: UIViewController?
+
   public let identifier = "PayWallPlugin"
   public let jsName = "PayWall"
   public let pluginMethods: [CAPPluginMethod] = [
@@ -12,14 +22,17 @@ public class PayWallPlugin: CAPPlugin, CAPBridgedPlugin {
   @objc func showPayWall(_ call: CAPPluginCall) {
     do {
       let type = try call.getStringEnsure("type")
+      let controller = try controller.get()
 
-      // TODO: Implement actual paywall logic here
-      // For now, just log the type and resolve
-      print("PayWall: Showing paywall of type: \(type)")
+      // TODO: GET TO KNOW THE PAYWALL TYPE
+      print("[*] showing paywall of type: \(type)")
+      DispatchQueue.main.async {
+        Paywall.presentWall(toController: controller, type: type)
+      }
 
       call.resolve(["success": true, "type": type])
     } catch {
-      call.reject("Failed to show paywall", nil, error)
+      call.reject("failed to show paywall", nil, error)
     }
   }
-}
+}

packages/frontend/apps/ios/App/App/Tools.swift

@@ -0,0 +1,21 @@
+//
+//  Tools.swift
+//  AFFiNE
+//
+//  Created by qaq on 9/18/25.
+//
+
+import Foundation
+
+extension Optional {
+  func get(_ failure: String? = nil) throws -> Wrapped {
+    guard let self else {
+      if let failure {
+        throw NSError(domain: #function, code: -1, userInfo: [NSLocalizedDescriptionKey: failure])
+      } else {
+        throw NSError(domain: #function, code: -1)
+      }
+    }
+    return self
+  }
+}