fix: iOS BugCollect 修复 warn() 和 freeMemoryMb

修复：
- warn() 添加 breadcrumbs 和 device 信息
- freeMemoryMb 改为使用 os_proc_available_memory() 获取可用内存
- 添加 iOS 13+ 版本检查

Co-Authored-By: Claude <noreply@anthropic.com>

Sources/XuqmBugCollectSDK/BugCollectSDK.swift

@@ -153,17 +153,19 @@ public final class BugCollectSDK {
         guard logLevel.rawValue <= LogLevel.warn.rawValue else { return }
         guard isReady() else { return }
 
+        let crumbs = breadcrumbLock.lockAndRun { breadcrumbBuffer }
         let issueEvent = IssueEvent(
             level: "warning",
             platform: "ios",
             fingerprint: Fingerprint.compute(type: "Warning", message: message, stacktrace: ""),
             appKey: XuqmSDK.shared.requireConfig().appKey,
             exception: IssueEvent.ExceptionInfo(type: "Warning", value: message),
-            breadcrumbs: [],
+            breadcrumbs: crumbs,
             release: appVersion(),
             environment: environment,
             userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
             user: IssueEvent.UserInfo(id: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId),
+            device: buildDeviceInfo(),
             tags: tags
         )
         queue?.push(issueEvent)
@@ -249,6 +251,16 @@ public final class BugCollectSDK {
         let device = UIDevice.current
         let processInfo = ProcessInfo.processInfo
 
+        // 使用 os_proc_available_memory() 获取可用内存（如果可用）
+        let freeMemoryMb: Int
+        if #available(iOS 13.0, *) {
+            let availableMemory = os_proc_available_memory()
+            freeMemoryMb = Int(availableMemory / 1024 / 1024)
+        } else {
+            // Fallback: 使用物理内存（不准确但有值）
+            freeMemoryMb = Int(processInfo.physicalMemory / 1024 / 1024)
+        }
+
         return IssueEvent.DeviceInfo(
             model: device.model,
             manufacturer: "Apple",
@@ -257,7 +269,7 @@ public final class BugCollectSDK {
             locale: Locale.current.identifier,
             timezone: TimeZone.current.identifier,
             isEmulator: isSimulator(),
-            freeMemoryMb: Int(processInfo.physicalMemory / 1024 / 1024),
+            freeMemoryMb: freeMemoryMb,
             buildType: isDebug() ? "debug" : "release"
         )
     }