feat: make storage tier thresholds configurable in system settings

Add StorageGreenThresholdPercent (default 30%) and StorageRedThresholdPercent
(default 10%) to both SystemSettingsDto and the settings UI.

StorageGuardService now reads thresholds from settings instead of hardcoding.

Co-Authored-By: Claude Opus 4.8 noreply@anthropic.com

frontend/src/types.ts

@@ -421,6 +421,8 @@ export interface SystemSettings {
   enableStorageGuard: boolean;
   pauseRecordingWhenFreeSpaceBelowMegabytes: number;
   resumeRecordingWhenFreeSpaceAboveMegabytes: number;
+  storageGreenThresholdPercent: number;
+  storageRedThresholdPercent: number;
   enableRetentionCleanup: boolean;
   retentionDays: number;
   retentionDeleteFiles: boolean;

frontend/src/views/SettingsView.vue

@@ -106,6 +106,8 @@ const form = reactive<SettingsFormModel>({
   enableStorageGuard: true,
   pauseRecordingWhenFreeSpaceBelowMegabytes: 1024,
   resumeRecordingWhenFreeSpaceAboveMegabytes: 4096,
+  storageGreenThresholdPercent: 30,
+  storageRedThresholdPercent: 10,
   enableRetentionCleanup: false,
   retentionDays: 30,
   retentionDeleteFiles: false,
@@ -1097,10 +1099,37 @@ watch(
               </el-form-item>
             </el-col>
           </el-row>
+          <el-row :gutter="16" style="margin-top: 16px">
+            <el-col :span="12">
+              <el-form-item label="绿色水位线：剩余空间高于 (%)">
+                <el-input-number
+                  v-model="form.storageGreenThresholdPercent"
+                  :min="5"
+                  :max="90"
+                  :step="5"
+                  :disabled="!form.enableStorageGuard"
+                />
+                <div class="field-hint">高于此比例时正常录制，低于时拒绝新录制</div>
+              </el-form-item>
+            </el-col>
+            <el-col :span="12">
+              <el-form-item label="红色水位线：剩余空间低于 (%)">
+                <el-input-number
+                  v-model="form.storageRedThresholdPercent"
+                  :min="1"
+                  :max="85"
+                  :step="5"
+                  :disabled="!form.enableStorageGuard"
+                />
+                <div class="field-hint">低于此比例时暂停所有录制和转码，仅保留上传</div>
+              </el-form-item>
+            </el-col>
+          </el-row>
         </el-form>
 
         <div class="helper-panel">
-          恢复阈值建议高于暂停阈值，避免磁盘空间在临界值附近反复抖动。MP4 转码会额外占用中间 TS 文件空间。
+          恢复阈值建议高于暂停阈值，避免磁盘空间在临界值附近反复抖动。MP4 转码会额外占用中间 TS 文件空间。<br/>
+          绿色/红色水位线控制三级存储保护：<b>绿色</b>(正常录制) → <b>黄色</b>(拒绝新录制，现有继续转码上传) → <b>红色</b>(暂停所有录制转码，仅上传清盘)。
         </div>
       </el-card>
 

src/LiveRecorder.Application/Models/Settings/SettingsModels.cs

@@ -112,6 +112,12 @@ public sealed class SystemSettingsDto
 
     public int ResumeRecordingWhenFreeSpaceAboveMegabytes { get; set; } = 4096;
 
+    /// <summary>Disk free percentage above which storage is considered healthy (Green tier). Default 30%.</summary>
+    public double StorageGreenThresholdPercent { get; set; } = 30;
+
+    /// <summary>Disk free percentage below which storage is critical (Red tier). Default 10%.</summary>
+    public double StorageRedThresholdPercent { get; set; } = 10;
+
     public bool EnableAutoReconnect { get; set; } = true;
 
     public int ReconnectDelayMaxSeconds { get; set; } = 5;
@@ -385,6 +391,12 @@ public sealed class UpdateSystemSettingsRequest
 
     public int ResumeRecordingWhenFreeSpaceAboveMegabytes { get; set; } = 4096;
 
+    /// <summary>Disk free percentage above which storage is considered healthy (Green tier). Default 30%.</summary>
+    public double StorageGreenThresholdPercent { get; set; } = 30;
+
+    /// <summary>Disk free percentage below which storage is critical (Red tier). Default 10%.</summary>
+    public double StorageRedThresholdPercent { get; set; } = 10;
+
     public bool EnableAutoReconnect { get; set; } = true;
 
     public int ReconnectDelayMaxSeconds { get; set; } = 5;

src/LiveRecorder.Application/Services/SystemSettingsService.cs

@@ -5,6 +5,7 @@ using LiveRecorder.Application.Models.Cleanup;
 using LiveRecorder.Application.Models.Settings;
 using LiveRecorder.Domain.Entities;
 using LiveRecorder.Domain.Enums;
+using System.Globalization;
 using System.Text.Json;
 
 namespace LiveRecorder.Application.Services;
@@ -25,6 +26,8 @@ public sealed class SystemSettingsService : ISystemSettingsService
     private const string EnableStorageGuardKey = "storage.guard.enabled";
     private const string PauseRecordingWhenFreeSpaceBelowMegabytesKey = "storage.guard.pause_recording_below_mb";
     private const string ResumeRecordingWhenFreeSpaceAboveMegabytesKey = "storage.guard.resume_recording_above_mb";
+    private const string StorageGreenThresholdPercentKey = "storage.guard.green_threshold_percent";
+    private const string StorageRedThresholdPercentKey = "storage.guard.red_threshold_percent";
     private const string EnableReconnectKey = "recording.enable_auto_reconnect";
     private const string ReconnectDelayMaxSecondsKey = "recording.reconnect_delay_max_seconds";
     private const string ReadWriteTimeoutMillisecondsKey = "recording.read_write_timeout_milliseconds";
@@ -140,6 +143,8 @@ public sealed class SystemSettingsService : ISystemSettingsService
             EnableStorageGuard = bool.TryParse(GetValue(lookup, EnableStorageGuardKey, "true"), out var enableStorageGuard) && enableStorageGuard,
             PauseRecordingWhenFreeSpaceBelowMegabytes = GetIntValue(lookup, PauseRecordingWhenFreeSpaceBelowMegabytesKey, 1024, 0, 1048576),
             ResumeRecordingWhenFreeSpaceAboveMegabytes = GetIntValue(lookup, ResumeRecordingWhenFreeSpaceAboveMegabytesKey, 4096, 0, 1048576),
+            StorageGreenThresholdPercent = GetDoubleValue(lookup, StorageGreenThresholdPercentKey, 30, 5, 90),
+            StorageRedThresholdPercent = GetDoubleValue(lookup, StorageRedThresholdPercentKey, 10, 1, 85),
             EnableAutoReconnect = bool.TryParse(GetValue(lookup, EnableReconnectKey, "true"), out var enableReconnect) && enableReconnect,
             ReconnectDelayMaxSeconds = GetIntValue(lookup, ReconnectDelayMaxSecondsKey, 5, 1, 300),
             ReadWriteTimeoutMilliseconds = GetIntValue(lookup, ReadWriteTimeoutMillisecondsKey, 15000000, 1000, 60000000),
@@ -307,6 +312,16 @@ public sealed class SystemSettingsService : ISystemSettingsService
             Math.Clamp(request.ResumeRecordingWhenFreeSpaceAboveMegabytes, 0, 1048576).ToString(),
             now,
             cancellationToken);
+        await UpsertAsync(
+            StorageGreenThresholdPercentKey,
+            Math.Clamp(request.StorageGreenThresholdPercent, 5, 90).ToString("F1", CultureInfo.InvariantCulture),
+            now,
+            cancellationToken);
+        await UpsertAsync(
+            StorageRedThresholdPercentKey,
+            Math.Clamp(request.StorageRedThresholdPercent, 1, 85).ToString("F1", CultureInfo.InvariantCulture),
+            now,
+            cancellationToken);
         await UpsertAsync(EnableReconnectKey, request.EnableAutoReconnect.ToString(), now, cancellationToken);
         await UpsertAsync(ReconnectDelayMaxSecondsKey, request.ReconnectDelayMaxSeconds.ToString(), now, cancellationToken);
         await UpsertAsync(ReadWriteTimeoutMillisecondsKey, request.ReadWriteTimeoutMilliseconds.ToString(), now, cancellationToken);
@@ -466,6 +481,22 @@ public sealed class SystemSettingsService : ISystemSettingsService
         return Math.Clamp(parsedValue, minimum, maximum);
     }
 
+    private static double GetDoubleValue(
+        IReadOnlyDictionary<string, string> lookup,
+        string key,
+        double fallback,
+        double minimum,
+        double maximum)
+    {
+        var raw = GetValue(lookup, key, fallback.ToString(CultureInfo.InvariantCulture));
+        if (!double.TryParse(raw, NumberStyles.Float, CultureInfo.InvariantCulture, out var parsedValue))
+        {
+            return fallback;
+        }
+
+        return Math.Clamp(parsedValue, minimum, maximum);
+    }
+
     private static IReadOnlyList<int> GetIntListValue(IReadOnlyDictionary<string, string> lookup, string key)
     {
         if (!lookup.TryGetValue(key, out var raw) || string.IsNullOrWhiteSpace(raw))

src/LiveRecorder.Infrastructure/Services/StorageGuardService.cs

@@ -7,8 +7,6 @@ namespace LiveRecorder.Infrastructure.Services;
 public sealed class StorageGuardService : IStorageGuardService
 {
     private const long Megabyte = 1024L * 1024L;
-    private const double GreenThresholdPercent = 30.0;
-    private const double YellowThresholdPercent = 10.0;
     private readonly ILogger<StorageGuardService> _logger;
 
     public StorageGuardService(ILogger<StorageGuardService> logger)
@@ -46,13 +44,16 @@ public sealed class StorageGuardService : IStorageGuardService
             var usagePercent = totalBytes > 0 ? (double)usedBytes / totalBytes * 100.0 : 0;
             var freePercent = 100.0 - usagePercent;
 
-            // Determine tier
+            // Determine tier using configurable thresholds
+            var greenThreshold = Math.Clamp(settings.StorageGreenThresholdPercent, 5, 90);
+            var redThreshold = Math.Clamp(settings.StorageRedThresholdPercent, 1, greenThreshold - 1);
+
             StorageTier tier;
-            if (freePercent >= GreenThresholdPercent)
+            if (freePercent >= greenThreshold)
             {
                 tier = StorageTier.Green;
             }
-            else if (freePercent >= YellowThresholdPercent)
+            else if (freePercent >= redThreshold)
             {
                 tier = StorageTier.Yellow;
             }