在 MiGu 侧落地日志定时清理与磁盘空间告警。

系统配置可开关清理策略；日志管理页支持查看/保存清理选项。

Co-authored-by: Cursor <cursoragent@cursor.com>

MiGu.Server/Configs/ConfigStore.cs

@@ -7,7 +7,7 @@ namespace MiGu.Server.Configs;
 /// <summary>
 /// 配置中心存储（内存 + JSON 文件持久化占位）。
 /// 前 14 个 section 对应 ARCHITECTURE.md §9 的 13+1 维度；外加 deployment —— 登录后「配置向导」的部署画像。
-/// 真实落地时由 SimpleShared.Persistence 接入 EF Core，并配合 YARP 下发至 SimpleLite。
+/// 真实落地时由 SimpleShared.Persistence 接入 EF Core，并配合 YARP 下发至 Simple3。
 /// </summary>
 public sealed class ConfigStore
 {
@@ -99,6 +99,58 @@ public sealed class ConfigStore
         return Put("deployment", el);
     }
 
+    public LogCleanupOptions GetLogCleanup()
+    {
+        var env = Get("system");
+        return env.Payload switch
+        {
+            SystemConfig sc => (sc.LogCleanup ?? new LogCleanupOptions()).Clamp(),
+            JsonElement el => ParseLogCleanup(el),
+            _ => LogCleanupOptions.CreateDefaults()
+        };
+    }
+
+    public Envelope PutLogCleanup(LogCleanupOptions options)
+    {
+        var opt = (options ?? new LogCleanupOptions()).Clamp();
+        Dictionary<string, JsonElement> dict;
+        try
+        {
+            var current = Get("system").Payload;
+            var el = current is JsonElement je
+                ? je
+                : JsonSerializer.SerializeToElement(current, _jsonOpts);
+            dict = el.ValueKind == JsonValueKind.Object
+                ? JsonSerializer.Deserialize<Dictionary<string, JsonElement>>(el.GetRawText()) ?? new()
+                : new Dictionary<string, JsonElement>();
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "读取 system 配置失败，按空对象合并 logCleanup");
+            dict = new Dictionary<string, JsonElement>();
+        }
+
+        dict["logCleanup"] = JsonSerializer.SerializeToElement(opt, _jsonOpts);
+        var merged = JsonSerializer.SerializeToElement(dict, _jsonOpts);
+        return Put("system", merged);
+    }
+
+    private LogCleanupOptions ParseLogCleanup(JsonElement el)
+    {
+        try
+        {
+            if (el.ValueKind == JsonValueKind.Object && el.TryGetProperty("logCleanup", out var nested))
+                return (nested.Deserialize<LogCleanupOptions>(_jsonOpts) ?? new LogCleanupOptions()).Clamp();
+            var sc = el.Deserialize<SystemConfig>(_jsonOpts);
+            return (sc?.LogCleanup ?? new LogCleanupOptions()).Clamp();
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "反序列化 logCleanup 失败，回退默认值");
+            return LogCleanupOptions.CreateDefaults();
+        }
+    }
+
     private DeploymentProfile SafeDeserializeDeployment(JsonElement el)
     {
         try { return el.Deserialize<DeploymentProfile>(_jsonOpts) ?? DeploymentProfile.Default(); }