feat: add JoeAppEngine OPC UA nodes, fix DCL auto-reconnect and quality push

- Add JoeAppEngine folder to OPC UA nodes.json (BTCS, AlarmCntsBySeverity, Scheduler/ScanTime)
- Fix DataConnectionActor: capture Self in PreStart for use from non-actor threads,
  preventing Self.Tell failure in Disconnected event handler
- Implement InstanceActor.HandleConnectionQualityChanged to mark attributes Bad on disconnect
- Fix LmxFakeProxy TagMapper to serialize arrays as JSON instead of "System.Int32[]"
- Allow DataType and DataSourceReference updates in TemplateService.UpdateAttributeAsync
- Update test_infra_opcua.md with JoeAppEngine documentation

src/ScadaLink.CentralUI/Components/Pages/Design/ExternalSystems.razor

@@ -50,8 +50,8 @@
 
         @if (_tab == "extsys") { @RenderExternalSystems() }
         else if (_tab == "dbconn") { @RenderDbConnections() }
-        else if (_tab == "notif") { @RenderNotificationLists() }
-        else if (_tab == "inbound") { @RenderInboundApiMethods() }
+        else if (_tab == "notif") { @RenderNotificationLists() @RenderSmtpConfig() }
+        else if (_tab == "inbound") { @RenderInboundApiMethods() @RenderApiKeyMethodAssignments() }
     }
 </div>
 
@@ -66,6 +66,8 @@
     private ExternalSystemDefinition? _editingExtSys;
     private string _extSysName = "", _extSysUrl = "", _extSysAuth = "ApiKey";
     private string? _extSysAuthConfig;
+    private int _extSysMaxRetries = 3;
+    private int _extSysRetryDelaySeconds = 5;
     private string? _extSysFormError;
 
     // Database Connections
@@ -73,8 +75,21 @@
     private bool _showDbConnForm;
     private DatabaseConnectionDefinition? _editingDbConn;
     private string _dbConnName = "", _dbConnString = "";
+    private int _dbConnMaxRetries = 3;
+    private int _dbConnRetryDelaySeconds = 5;
     private string? _dbConnFormError;
 
+    // SMTP Configuration
+    private List<SmtpConfiguration> _smtpConfigs = new();
+    private bool _showSmtpForm;
+    private SmtpConfiguration? _editingSmtp;
+    private string _smtpHost = "", _smtpFromAddress = "", _smtpAuthType = "OAuth2";
+    private int _smtpPort = 587;
+    private string? _smtpFormError;
+
+    // API Key list
+    private List<ApiKey> _apiKeys = new();
+
     // Notification Lists
     private List<NotificationList> _notificationLists = new();
     private bool _showNotifForm;
@@ -123,6 +138,8 @@
             }
 
             _apiMethods = (await InboundApiRepository.GetAllApiMethodsAsync()).ToList();
+            _smtpConfigs = (await NotificationRepository.GetAllSmtpConfigurationsAsync()).ToList();
+            _apiKeys = (await InboundApiRepository.GetAllApiKeysAsync()).ToList();
         }
         catch (Exception ex) { _errorMessage = ex.Message; }
         _loading = false;
@@ -144,8 +161,10 @@
                     <div class="col-md-3"><label class="form-label small">Endpoint URL</label><input type="text" class="form-control form-control-sm" @bind="_extSysUrl" /></div>
                     <div class="col-md-2"><label class="form-label small">Auth Type</label>
                         <select class="form-select form-select-sm" @bind="_extSysAuth"><option>ApiKey</option><option>BasicAuth</option></select></div>
-                    <div class="col-md-3"><label class="form-label small">Auth Config (JSON)</label><input type="text" class="form-control form-control-sm" @bind="_extSysAuthConfig" /></div>
-                    <div class="col-md-2">
+                    <div class="col-md-2"><label class="form-label small">Auth Config (JSON)</label><input type="text" class="form-control form-control-sm" @bind="_extSysAuthConfig" /></div>
+                    <div class="col-md-1"><label class="form-label small">Max Retries</label><input type="number" class="form-control form-control-sm" @bind="_extSysMaxRetries" min="0" /></div>
+                    <div class="col-md-1"><label class="form-label small">Retry Delay (s)</label><input type="number" class="form-control form-control-sm" @bind="_extSysRetryDelaySeconds" min="0" /></div>
+                    <div class="col-md-1">
                         <button class="btn btn-success btn-sm me-1" @onclick="SaveExtSys">Save</button>
                         <button class="btn btn-outline-secondary btn-sm" @onclick="() => _showExtSysForm = false">Cancel</button></div>
                 </div>
@@ -154,14 +173,15 @@
         }
 
         <table class="table table-sm table-striped">
-            <thead class="table-dark"><tr><th>Name</th><th>URL</th><th>Auth</th><th style="width:120px;">Actions</th></tr></thead>
+            <thead class="table-dark"><tr><th>Name</th><th>URL</th><th>Auth</th><th>Retries</th><th>Delay</th><th style="width:120px;">Actions</th></tr></thead>
             <tbody>
                 @foreach (var es in _externalSystems)
                 {
                     <tr>
                         <td>@es.Name</td><td class="small">@es.EndpointUrl</td><td><span class="badge bg-secondary">@es.AuthType</span></td>
+                        <td class="small">@es.MaxRetries</td><td class="small">@es.RetryDelay.TotalSeconds s</td>
                         <td>
-                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1" @onclick="() => { _editingExtSys = es; _extSysName = es.Name; _extSysUrl = es.EndpointUrl; _extSysAuth = es.AuthType; _extSysAuthConfig = es.AuthConfiguration; _showExtSysForm = true; }">Edit</button>
+                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1" @onclick="() => { _editingExtSys = es; _extSysName = es.Name; _extSysUrl = es.EndpointUrl; _extSysAuth = es.AuthType; _extSysAuthConfig = es.AuthConfiguration; _extSysMaxRetries = es.MaxRetries; _extSysRetryDelaySeconds = (int)es.RetryDelay.TotalSeconds; _showExtSysForm = true; }">Edit</button>
                             <button class="btn btn-outline-danger btn-sm py-0 px-1" @onclick="() => DeleteExtSys(es)">Delete</button>
                         </td>
                     </tr>
@@ -177,6 +197,8 @@
         _extSysName = _extSysUrl = string.Empty;
         _extSysAuth = "ApiKey";
         _extSysAuthConfig = null;
+        _extSysMaxRetries = 3;
+        _extSysRetryDelaySeconds = 5;
         _extSysFormError = null;
     }
 
@@ -186,8 +208,8 @@
         if (string.IsNullOrWhiteSpace(_extSysName) || string.IsNullOrWhiteSpace(_extSysUrl)) { _extSysFormError = "Name and URL required."; return; }
         try
         {
-            if (_editingExtSys != null) { _editingExtSys.Name = _extSysName.Trim(); _editingExtSys.EndpointUrl = _extSysUrl.Trim(); _editingExtSys.AuthType = _extSysAuth; _editingExtSys.AuthConfiguration = _extSysAuthConfig?.Trim(); await ExternalSystemRepository.UpdateExternalSystemAsync(_editingExtSys); }
-            else { var es = new ExternalSystemDefinition(_extSysName.Trim(), _extSysUrl.Trim(), _extSysAuth) { AuthConfiguration = _extSysAuthConfig?.Trim() }; await ExternalSystemRepository.AddExternalSystemAsync(es); }
+            if (_editingExtSys != null) { _editingExtSys.Name = _extSysName.Trim(); _editingExtSys.EndpointUrl = _extSysUrl.Trim(); _editingExtSys.AuthType = _extSysAuth; _editingExtSys.AuthConfiguration = _extSysAuthConfig?.Trim(); _editingExtSys.MaxRetries = _extSysMaxRetries; _editingExtSys.RetryDelay = TimeSpan.FromSeconds(_extSysRetryDelaySeconds); await ExternalSystemRepository.UpdateExternalSystemAsync(_editingExtSys); }
+            else { var es = new ExternalSystemDefinition(_extSysName.Trim(), _extSysUrl.Trim(), _extSysAuth) { AuthConfiguration = _extSysAuthConfig?.Trim(), MaxRetries = _extSysMaxRetries, RetryDelay = TimeSpan.FromSeconds(_extSysRetryDelaySeconds) }; await ExternalSystemRepository.AddExternalSystemAsync(es); }
             await ExternalSystemRepository.SaveChangesAsync(); _showExtSysForm = false; _toast.ShowSuccess("Saved."); await LoadAllAsync();
         }
         catch (Exception ex) { _extSysFormError = ex.Message; }
@@ -205,7 +227,7 @@
     {
         <div class="d-flex justify-content-between mb-2">
             <h6 class="mb-0">Database Connections</h6>
-            <button class="btn btn-primary btn-sm" @onclick="() => { _showDbConnForm = true; _editingDbConn = null; _dbConnName = _dbConnString = string.Empty; _dbConnFormError = null; }">Add</button>
+            <button class="btn btn-primary btn-sm" @onclick="() => { _showDbConnForm = true; _editingDbConn = null; _dbConnName = _dbConnString = string.Empty; _dbConnMaxRetries = 3; _dbConnRetryDelaySeconds = 5; _dbConnFormError = null; }">Add</button>
         </div>
 
         @if (_showDbConnForm)
@@ -213,7 +235,9 @@
             <div class="card mb-2"><div class="card-body">
                 <div class="row g-2 align-items-end">
                     <div class="col-md-3"><label class="form-label small">Name</label><input type="text" class="form-control form-control-sm" @bind="_dbConnName" /></div>
-                    <div class="col-md-6"><label class="form-label small">Connection String</label><input type="text" class="form-control form-control-sm" @bind="_dbConnString" /></div>
+                    <div class="col-md-4"><label class="form-label small">Connection String</label><input type="text" class="form-control form-control-sm" @bind="_dbConnString" /></div>
+                    <div class="col-md-1"><label class="form-label small">Max Retries</label><input type="number" class="form-control form-control-sm" @bind="_dbConnMaxRetries" min="0" /></div>
+                    <div class="col-md-1"><label class="form-label small">Retry Delay (s)</label><input type="number" class="form-control form-control-sm" @bind="_dbConnRetryDelaySeconds" min="0" /></div>
                     <div class="col-md-3">
                         <button class="btn btn-success btn-sm me-1" @onclick="SaveDbConn">Save</button>
                         <button class="btn btn-outline-secondary btn-sm" @onclick="() => _showDbConnForm = false">Cancel</button></div>
@@ -223,14 +247,15 @@
         }
 
         <table class="table table-sm table-striped">
-            <thead class="table-dark"><tr><th>Name</th><th>Connection String</th><th style="width:120px;">Actions</th></tr></thead>
+            <thead class="table-dark"><tr><th>Name</th><th>Connection String</th><th>Retries</th><th>Delay</th><th style="width:120px;">Actions</th></tr></thead>
             <tbody>
                 @foreach (var dc in _dbConnections)
                 {
                     <tr>
                         <td>@dc.Name</td><td class="small text-muted text-truncate" style="max-width:400px;">@dc.ConnectionString</td>
+                        <td class="small">@dc.MaxRetries</td><td class="small">@dc.RetryDelay.TotalSeconds s</td>
                         <td>
-                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1" @onclick="() => { _editingDbConn = dc; _dbConnName = dc.Name; _dbConnString = dc.ConnectionString; _showDbConnForm = true; }">Edit</button>
+                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1" @onclick="() => { _editingDbConn = dc; _dbConnName = dc.Name; _dbConnString = dc.ConnectionString; _dbConnMaxRetries = dc.MaxRetries; _dbConnRetryDelaySeconds = (int)dc.RetryDelay.TotalSeconds; _showDbConnForm = true; }">Edit</button>
                             <button class="btn btn-outline-danger btn-sm py-0 px-1" @onclick="() => DeleteDbConn(dc)">Delete</button>
                         </td>
                     </tr>
@@ -245,8 +270,8 @@
         if (string.IsNullOrWhiteSpace(_dbConnName) || string.IsNullOrWhiteSpace(_dbConnString)) { _dbConnFormError = "Name and connection string required."; return; }
         try
         {
-            if (_editingDbConn != null) { _editingDbConn.Name = _dbConnName.Trim(); _editingDbConn.ConnectionString = _dbConnString.Trim(); await ExternalSystemRepository.UpdateDatabaseConnectionAsync(_editingDbConn); }
-            else { var dc = new DatabaseConnectionDefinition(_dbConnName.Trim(), _dbConnString.Trim()); await ExternalSystemRepository.AddDatabaseConnectionAsync(dc); }
+            if (_editingDbConn != null) { _editingDbConn.Name = _dbConnName.Trim(); _editingDbConn.ConnectionString = _dbConnString.Trim(); _editingDbConn.MaxRetries = _dbConnMaxRetries; _editingDbConn.RetryDelay = TimeSpan.FromSeconds(_dbConnRetryDelaySeconds); await ExternalSystemRepository.UpdateDatabaseConnectionAsync(_editingDbConn); }
+            else { var dc = new DatabaseConnectionDefinition(_dbConnName.Trim(), _dbConnString.Trim()) { MaxRetries = _dbConnMaxRetries, RetryDelay = TimeSpan.FromSeconds(_dbConnRetryDelaySeconds) }; await ExternalSystemRepository.AddDatabaseConnectionAsync(dc); }
             await ExternalSystemRepository.SaveChangesAsync(); _showDbConnForm = false; _toast.ShowSuccess("Saved."); await LoadAllAsync();
         }
         catch (Exception ex) { _dbConnFormError = ex.Message; }
@@ -434,4 +459,127 @@
         try { await InboundApiRepository.DeleteApiMethodAsync(m.Id); await InboundApiRepository.SaveChangesAsync(); _toast.ShowSuccess("Deleted."); await LoadAllAsync(); }
         catch (Exception ex) { _toast.ShowError(ex.Message); }
     }
+
+    // ==== SMTP Configuration ====
+    private RenderFragment RenderSmtpConfig() => __builder =>
+    {
+        <hr class="my-3" />
+        <div class="d-flex justify-content-between mb-2">
+            <h6 class="mb-0">SMTP Configuration</h6>
+            @if (_smtpConfigs.Count == 0)
+            {
+                <button class="btn btn-primary btn-sm" @onclick="ShowSmtpAddForm">Add SMTP Config</button>
+            }
+        </div>
+
+        @if (_showSmtpForm)
+        {
+            <div class="card mb-2"><div class="card-body">
+                <div class="row g-2 align-items-end">
+                    <div class="col-md-3"><label class="form-label small">Host</label><input type="text" class="form-control form-control-sm" @bind="_smtpHost" /></div>
+                    <div class="col-md-1"><label class="form-label small">Port</label><input type="number" class="form-control form-control-sm" @bind="_smtpPort" /></div>
+                    <div class="col-md-2"><label class="form-label small">Auth Type</label>
+                        <select class="form-select form-select-sm" @bind="_smtpAuthType"><option>OAuth2</option><option>Basic</option></select></div>
+                    <div class="col-md-3"><label class="form-label small">From Address</label><input type="email" class="form-control form-control-sm" @bind="_smtpFromAddress" /></div>
+                    <div class="col-md-3">
+                        <button class="btn btn-success btn-sm me-1" @onclick="SaveSmtpConfig">Save</button>
+                        <button class="btn btn-outline-secondary btn-sm" @onclick="() => _showSmtpForm = false">Cancel</button></div>
+                </div>
+                @if (_smtpFormError != null) { <div class="text-danger small mt-1">@_smtpFormError</div> }
+            </div></div>
+        }
+
+        @foreach (var smtp in _smtpConfigs)
+        {
+            <div class="card mb-2">
+                <div class="card-body py-2">
+                    <div class="d-flex justify-content-between align-items-center">
+                        <span class="small">
+                            <strong>@smtp.Host</strong>:@smtp.Port |
+                            Auth: <span class="badge bg-secondary">@smtp.AuthType</span> |
+                            From: @smtp.FromAddress
+                        </span>
+                        <button class="btn btn-outline-primary btn-sm py-0 px-1" @onclick="() => { _editingSmtp = smtp; _smtpHost = smtp.Host; _smtpPort = smtp.Port; _smtpAuthType = smtp.AuthType; _smtpFromAddress = smtp.FromAddress; _showSmtpForm = true; }">Edit</button>
+                    </div>
+                </div>
+            </div>
+        }
+    };
+
+    private void ShowSmtpAddForm()
+    {
+        _showSmtpForm = true;
+        _editingSmtp = null;
+        _smtpHost = string.Empty;
+        _smtpPort = 587;
+        _smtpAuthType = "OAuth2";
+        _smtpFromAddress = string.Empty;
+        _smtpFormError = null;
+    }
+
+    private async Task SaveSmtpConfig()
+    {
+        _smtpFormError = null;
+        if (string.IsNullOrWhiteSpace(_smtpHost) || string.IsNullOrWhiteSpace(_smtpFromAddress)) { _smtpFormError = "Host and From Address required."; return; }
+        try
+        {
+            if (_editingSmtp != null)
+            {
+                _editingSmtp.Host = _smtpHost.Trim();
+                _editingSmtp.Port = _smtpPort;
+                _editingSmtp.AuthType = _smtpAuthType;
+                _editingSmtp.FromAddress = _smtpFromAddress.Trim();
+                await NotificationRepository.UpdateSmtpConfigurationAsync(_editingSmtp);
+            }
+            else
+            {
+                var smtp = new SmtpConfiguration(_smtpHost.Trim(), _smtpAuthType, _smtpFromAddress.Trim()) { Port = _smtpPort };
+                await NotificationRepository.AddSmtpConfigurationAsync(smtp);
+            }
+            await NotificationRepository.SaveChangesAsync();
+            _showSmtpForm = false;
+            _toast.ShowSuccess("SMTP configuration saved.");
+            await LoadAllAsync();
+        }
+        catch (Exception ex) { _smtpFormError = ex.Message; }
+    }
+
+    // ==== API Key → Method Assignments ====
+    private RenderFragment RenderApiKeyMethodAssignments() => __builder =>
+    {
+        <hr class="my-3" />
+        <div class="d-flex justify-content-between mb-2">
+            <h6 class="mb-0">API Keys</h6>
+        </div>
+
+        <table class="table table-sm table-striped">
+            <thead class="table-dark"><tr><th>Key Name</th><th>Enabled</th><th style="width:120px;">Actions</th></tr></thead>
+            <tbody>
+                @foreach (var key in _apiKeys)
+                {
+                    <tr>
+                        <td>@key.Name</td>
+                        <td><span class="badge @(key.IsEnabled ? "bg-success" : "bg-secondary")">@(key.IsEnabled ? "Enabled" : "Disabled")</span></td>
+                        <td>
+                            <button class="btn btn-outline-primary btn-sm py-0 px-1" @onclick="() => ToggleApiKeyEnabled(key)">
+                                @(key.IsEnabled ? "Disable" : "Enable")
+                            </button>
+                        </td>
+                    </tr>
+                }
+            </tbody>
+        </table>
+    };
+
+    private async Task ToggleApiKeyEnabled(ApiKey key)
+    {
+        try
+        {
+            key.IsEnabled = !key.IsEnabled;
+            await InboundApiRepository.UpdateApiKeyAsync(key);
+            await InboundApiRepository.SaveChangesAsync();
+            _toast.ShowSuccess($"API key '{key.Name}' {(key.IsEnabled ? "enabled" : "disabled")}.");
+        }
+        catch (Exception ex) { _toast.ShowError(ex.Message); }
+    }
 }