Phase 1.7：BridgeBus 实现 H5↔Native 消息总线 + WKScriptMessageHandler

桥核心的运行时层：把 BridgeProtocol 落到 WKWebView 上，承担 JS → Native
消息分发 + Native → H5 主动调用 + 双向 callback 配对。

- 新增 ylgamehall/Source/Bridge/BridgeBus.swift
  - @MainActor final class，BridgeProtocol + WKScriptMessageHandler 双重
    conform；init(webView:, controller:) 自动向 controller 注册 WVJBHandler
    通道
  - JS → Native（userContentController:didReceive:）
    - body 兼容单条 dict 与 batch [[dict]]
    - 优先识 responseId → 查 pendingCallbacks 派给 Native 端 callback
    - 否则按 handlerName 查 handlers，构造异步 responseCallback 闭包，
      handler 是 @Sendable async 用独立 Task 执行
  - Native → H5（call(_:data:callback:)）
    - 拼 payload {handlerName, data, callbackId?}，base64 后注入
      WebViewJavascriptBridge._handleMessageFromObjC('<base64>')
    - callback 用 nativeCallbackCounter 递增成 objc_cb_<n> 入
      pendingCallbacks，等 JS 响应回收
  - sendResponseToJS：拼 {responseId, responseData} 走同一通道
  - makeResponseCallback 辅助方法：把多层嵌套闭包拆出来，避免
    Swift 6 类型推断在深嵌套 + actor 隔离上 ICE
- 资源生命周期：webView 弱引用避免循环；BridgeBus 由 controller.add(self)
  retains，WebView 释放后 controller 一并清空 handler 列表自然 release
- BuildProject 通过，Swift 6 严格并发 0 warning；下一步 Phase 1.8 注入
  marcuswestin/WVJB JS 端配套协议即可双向消息打通

ylgamehall/Source/Bridge/BridgeBus.swift

@@ -0,0 +1,140 @@
+//
+//  BridgeBus.swift
+//  ylgamehall
+//
+//  BridgeProtocol 的具体实现 + WKScriptMessageHandler 适配。
+//  详见 docs/H5-Native-Implementation-Design.md §3.3。
+//
+
+import Foundation
+import WebKit
+
+/// H5 ↔ Native 消息总线。
+///
+/// **运行时约束**：必须挂在 WKWebView 上、@MainActor 单线程访问。
+/// **生命周期**：构造时自动向 `WKUserContentController` 注册 `WVJBHandler` 通道，
+///   销毁时由 WebView 链路自然释放（无需手动 remove）。
+@MainActor
+public final class BridgeBus: NSObject, BridgeProtocol, WKScriptMessageHandler {
+
+    /// JS → Native 的 WKScriptMessageHandler 通道名。
+    /// JS 端通过 `window.webkit.messageHandlers.WVJBHandler.postMessage({...})` 发送。
+    public static let scriptMessageHandlerName = "WVJBHandler"
+
+    /// JS 端注入的全局桥对象名（约定 `window.WebViewJavascriptBridge`）。
+    public static let jsBridgeName = "WebViewJavascriptBridge"
+
+    private weak var webView: WKWebView?
+    private var handlers: [String: BridgeHandler] = [:]
+    private var pendingCallbacks: [String: BridgeCallback] = [:]
+    private var nativeCallbackCounter: UInt64 = 0
+
+    /// 构造时绑定 WebView + 用户内容控制器，自动注册 `WVJBHandler` 消息处理器。
+    public init(webView: WKWebView, controller: WKUserContentController) {
+        self.webView = webView
+        super.init()
+        controller.add(self, name: Self.scriptMessageHandlerName)
+    }
+
+    // MARK: - BridgeProtocol
+
+    public func register(_ name: String, handler: @escaping BridgeHandler) {
+        handlers[name] = handler
+    }
+
+    public func call(_ name: String, data: BridgeData?, callback: BridgeCallback?) {
+        var payload: [String: Any] = ["handlerName": name]
+        if let data {
+            payload["data"] = data.jsonObject
+        }
+        if let callback {
+            nativeCallbackCounter += 1
+            let cbId = "objc_cb_\(nativeCallbackCounter)"
+            pendingCallbacks[cbId] = callback
+            payload["callbackId"] = cbId
+        }
+        sendToJS(payload: payload)
+    }
+
+    // MARK: - WKScriptMessageHandler
+
+    public func userContentController(_ userContentController: WKUserContentController,
+                                       didReceive message: WKScriptMessage) {
+        // body 可能是单条 dict 或一批 dict array（WVJB 支持批处理）
+        if let batch = message.body as? [[String: Any]] {
+            for msg in batch { handleIncoming(msg) }
+        } else if let single = message.body as? [String: Any] {
+            handleIncoming(single)
+        } else {
+            print("[BridgeBus] unrecognized message body type: \(type(of: message.body))")
+        }
+    }
+
+    // MARK: - 私有
+
+    private func handleIncoming(_ msg: [String: Any]) {
+        // 优先判 responseId（JS 响应 Native 早前的 callHandler）
+        if let responseId = msg["responseId"] as? String {
+            let respData = msg["responseData"].flatMap { BridgeData(jsonObject: $0) }
+            if let cb = pendingCallbacks.removeValue(forKey: responseId) {
+                cb(respData)
+            } else {
+                print("[BridgeBus] stale responseId: \(responseId)")
+            }
+            return
+        }
+
+        // 否则是 JS → Native handler 调用
+        guard let name = msg["handlerName"] as? String else {
+            print("[BridgeBus] message missing handlerName: \(msg)")
+            return
+        }
+        let data = msg["data"].flatMap { BridgeData(jsonObject: $0) }
+        let callbackId = msg["callbackId"] as? String
+
+        // 构造一个回调闭包，handler 调用即把 responseData 异步派回 JS
+        let responseCallback: BridgeCallback? = makeResponseCallback(for: callbackId)
+
+        guard let handler = handlers[name] else {
+            print("[BridgeBus] no handler registered for '\(name)'")
+            responseCallback?(nil)
+            return
+        }
+
+        // handler 是 async，独立 Task 内 await；本方法保持 sync 返回
+        Task {
+            await handler(data, responseCallback)
+        }
+    }
+
+    private func makeResponseCallback(for callbackId: String?) -> BridgeCallback? {
+        guard let id = callbackId else { return nil }
+        return { [weak self] respData in
+            Task { @MainActor in
+                self?.sendResponseToJS(responseId: id, data: respData)
+            }
+        }
+    }
+
+    private func sendResponseToJS(responseId: String, data: BridgeData?) {
+        var payload: [String: Any] = ["responseId": responseId]
+        if let data {
+            payload["responseData"] = data.jsonObject
+        }
+        sendToJS(payload: payload)
+    }
+
+    private func sendToJS(payload: [String: Any]) {
+        guard let webView else { return }
+        guard let data = try? JSONSerialization.data(withJSONObject: payload),
+              let json = String(data: data, encoding: .utf8)
+        else {
+            print("[BridgeBus] JSON encode failed for payload: \(payload)")
+            return
+        }
+        // base64 包装避免 JSON 内单引号 / 反斜杠扰乱 JS 字符串字面量
+        let base64 = Data(json.utf8).base64EncodedString()
+        let js = "if (window.\(Self.jsBridgeName)) window.\(Self.jsBridgeName)._handleMessageFromObjC('\(base64)');"
+        webView.evaluateJavaScript(js, completionHandler: nil)
+    }
+}