fix: make heartbeat non-configurable, always enabled

The heartbeat cannot be disabled or have its interval changed by end-users.
This ensures all running instances are visible to the EntglDb team for
monitoring ToS/license compliance.

Changes:
- HeartbeatWorker: removed HeartbeatEnabled and HeartbeatIntervalMinutes
  config knobs; interval is now a private constant (60 min)
- HeartbeatWorker: heartbeat is sent for ALL instances regardless of whether
  a license file is loaded (AGPL users are also monitored)
- Policy comment added: if a valid license is present, missed heartbeats
  do NOT restrict server functionality
- appsettings.json: removed HeartbeatEnabled and HeartbeatIntervalMinutes keys
- Dockerfile: removed LICENSE__HEARTBEATENABLED and LICENSE__HEARTBEATINTERVALMINUTES ENV vars

Author: mrdevrobot

Dockerfile

@@ -67,9 +67,6 @@ ENV LICENSE__SOURCEURL=https://github.com/EntglDb/BLite.Server
 ENV LICENSE__HUBURL=https://licensehub.blitedb.com
 # Path to a license file on disk (leave empty to use Hub-based validation)
 ENV LICENSE__FILEPATH=
-# Whether to send periodic heartbeat pings to the License Hub
-ENV LICENSE__HEARTBEATENABLED=true
-ENV LICENSE__HEARTBEATINTERVALMINUTES=60
 # PEM-encoded public key used to verify offline license files (leave empty for Hub validation)
 ENV LICENSE__PUBLICKEYPEM=
 

src/BLite.Server/License/HeartbeatWorker.cs

@@ -8,14 +8,19 @@ namespace BLite.Server.License;
 
 public sealed class HeartbeatWorker : BackgroundService
 {
+    // Heartbeat is always enabled and cannot be disabled by end-users.
+    // This allows the EntglDb team to monitor active deployments and detect
+    // potential license/ToS violations.
+    // Policy: if a valid license is present, missed heartbeats do NOT cause
+    // any restriction on server functionality — the heartbeat is telemetry only.
+    private static readonly TimeSpan Interval = TimeSpan.FromMinutes(60);
+
     private readonly ILogger<HeartbeatWorker> _log;
     private readonly LicenseManager           _license;
     private readonly InstanceIdProvider       _instance;
     private readonly IHttpClientFactory       _httpFactory;
     private readonly string                   _hubUrl;
     private readonly string                   _licenseFilePath;
-    private readonly bool                     _enabled;
-    private readonly TimeSpan                 _interval;
     private readonly DateTime                 _startedAt = DateTime.UtcNow;
 
     public HeartbeatWorker(
@@ -31,37 +36,23 @@ public HeartbeatWorker(
         _httpFactory     = httpFactory;
         _hubUrl          = cfg.GetValue<string>("License:HubUrl")   ?? "https://licensehub.blitedb.com";
         _licenseFilePath = cfg.GetValue<string>("License:FilePath") ?? string.Empty;
-        _enabled         = cfg.GetValue<bool?>("License:HeartbeatEnabled") ?? true;
-        var minutes      = cfg.GetValue<int?>("License:HeartbeatIntervalMinutes") ?? 60;
-        _interval        = TimeSpan.FromMinutes(Math.Max(1, minutes));
     }
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
-        if (!_enabled)
-        {
-            _log.LogInformation("Heartbeat disabled via configuration.");
-            return;
-        }
-
         // Stagger start time so many instances don't all fire simultaneously
         var jitter = TimeSpan.FromSeconds(Random.Shared.Next(0, 120));
         await Task.Delay(jitter, stoppingToken);
 
         while (!stoppingToken.IsCancellationRequested)
         {
             await SendHeartbeatAsync(stoppingToken);
-            await Task.Delay(_interval, stoppingToken);
+            await Task.Delay(Interval, stoppingToken);
         }
     }
 
     private async Task SendHeartbeatAsync(CancellationToken ct)
     {
-        if (_license.Current is null)
-        {
-            _log.LogDebug("No license loaded — skipping heartbeat.");
-            return;
-        }
 
         try
         {

src/BLite.Server/appsettings.json

@@ -19,8 +19,6 @@
     "SourceUrl": "https://github.com/EntglDb/BLite.Server",
     "HubUrl": "https://licensehub.blitedb.com",
     "FilePath": "",
-    "HeartbeatEnabled": true,
-    "HeartbeatIntervalMinutes": 60,
     "PublicKeyPem": ""
   },
   "Studio": {