refactor: 修复潜在bug、补全许可声明、添加类型注解、同步文档

main.rb

@@ -36,6 +36,17 @@ def main
 
   MethodExecutor.record("info", "mainloop", "MineSentinel started, entering mainloop.")
 
+  require_relative 'updates'
+
+  begin
+    upd_result = UpdateManager.check
+    if upd_result[:status] == :NewerAvailable
+      MethodExecutor.record("info", "updates", "Update #{upd_result[:version]} available, please check the git repo for details.")
+    end
+  rescue => check_error
+    MethodExecutor.record("error", "updates", "#{check_error.to_s}")
+  end
+
   # 初次启动：MineSentinel 先于 minecraft 启动（systemd Before=），
   # 等待服务器端口就绪，避免误判为崩溃
   MethodExecutor.record("info", "mainloop",
@@ -56,18 +67,18 @@ end
 # Functional mainloop.
 def main_once
   chkrslts = []
-  for i in 0..TRY_TIMES
+  (0..TRY_TIMES).each do
     chkrslt = ServerStatusDetector::MinecraftServer.self_diag
     chkrslts.append(chkrslt)
   end
   if chkrslts.all? { |chkrslt_in| chkrslt_in[:type] }
     MethodExecutor.record("debug", "mainloop", "Server health check passed.")
   else
-    for chkrslt_in in chkrslts
-      MethodExecutor.record("warn", "mainloop", "Server health check FAILED: #{chkrslt_in[:message]}")
+    chkrslts.each do |result|
+      MethodExecutor.record("warn", "mainloop", "Server health check FAILED: #{result[:message]}")
     end
     MethodExecutor.record("info", "mainloop", "Checked #{TRY_TIMES} time.")
-    if chkrslts.any? { |chkrslt_in| chkrslt_in[:operation] == "Record" }
+    if chkrslts.any? { |chkrslt_in| chkrslt_in[:operation].include?("Record") }
       MethodExecutor.record("warn", "mainloop", "Action: Record -> Server died!")
       if chkrslts.any? { |chkrslt_in| chkrslt_in[:message] == "Server died for unknown reason, and will be restarted." }
         MethodExecutor.record("info", "mainloop", "Action: ForceResetServerProcess triggered.")
@@ -98,6 +109,6 @@ begin
 rescue => e
   # 强制输出到stderr
   $stderr.puts "[CRITICAL] Unhandled exception: #{e.message}"
-  $stderr.puts e.backtrace.join("\n")
+  $stderr.puts e.backtrace&.join("\n")
   exit 1
 end