debug(bugcollect): 添加 flush 日志排查上传流程

sdk-bugcollect/src/main/java/com/xuqm/sdk/bugcollect/LogQueue.kt

@@ -111,7 +111,10 @@ internal class LogQueue(
 
     private fun flush() {
         // URL 未就绪时跳过，等下次定时 flush
-        if (logApiUrl.isBlank()) return
+        if (logApiUrl.isBlank()) {
+            Log.d(TAG, "flush: URL blank, skipping")
+            return
+        }
         val issues: List<IssueEvent>
         val events: List<LogEvent>
         synchronized(lock) {
@@ -121,6 +124,7 @@ internal class LogQueue(
             pendingIssues.clear()
             pendingEvents.clear()
         }
+        Log.d(TAG, "flush: uploading ${issues.size} issues, ${events.size} events, url=$logApiUrl")
         if (issues.isNotEmpty()) {
             scope.launch {
                 runCatching { LogUploader.uploadIssues(logApiUrl, issues) }