feat(twincat): opt-in ADS sum-read and /hosts diagnostics bag; refresh TwinCAT backlog (#645, #612)

Sum-read (#310): batches a poll's reads per device into sum commands capped at sumReadMaxItems,
per-item ADS errors mapped per tag, falls back to individual reads when the target refuses the
command. Diagnostics (#314): ADS state, app name, online-change count, task cycle/exec/jitter via
IDriverDiagnostics. Re-implemented against the current raw-byte read path (stranded auto/driver-gaps
commits predate it). Sum-write not ported. Unit tests only; live gate pending a route.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/Forms/TwinCATDriverForm.razor

@@ -43,6 +43,20 @@
                              class="form-control form-control-sm" />
                 <div class="form-text">0 = push immediately. Increase to coalesce high-churn signals.</div>
             </div>
+            <div class="col-md-4 mb-3">
+                <div class="form-check form-switch mt-4">
+                    <InputCheckbox id="tcSumRead" @bind-Value="_form.UseSumRead" @bind-Value:after="EmitAsync"
+                                   class="form-check-input" />
+                    <label class="form-check-label" for="tcSumRead">Batch polled reads (ADS sum-read)</label>
+                </div>
+                <div class="form-text">One round-trip per chunk instead of per tag. Falls back to single reads if the target refuses it. Default off.</div>
+            </div>
+            <div class="col-md-4 mb-3">
+                <label class="form-label" for="tcSumReadMax">Sum-read max items</label>
+                <InputNumber id="tcSumReadMax" @bind-Value="_form.SumReadMaxItems" @bind-Value:after="EmitAsync"
+                             class="form-control form-control-sm" />
+                <div class="form-text">Symbols per sum-read command (default 200).</div>
+            </div>
         </div>
     </div>
 </section>
@@ -151,6 +165,8 @@
         public bool UseNativeNotifications { get; set; } = true;
         public bool EnableControllerBrowse { get; set; } = false;
         public int NotificationMaxDelayMs { get; set; } = 0;
+        public bool UseSumRead { get; set; } = false;
+        public int SumReadMaxItems { get; set; } = 200;
 
         // Probe
         public bool ProbeEnabled { get; set; } = true;
@@ -168,6 +184,8 @@
             UseNativeNotifications = o.UseNativeNotifications,
             EnableControllerBrowse = o.EnableControllerBrowse,
             NotificationMaxDelayMs = o.NotificationMaxDelayMs,
+            UseSumRead = o.UseSumRead,
+            SumReadMaxItems = o.SumReadMaxItems,
             ProbeEnabled = o.Probe.Enabled,
             ProbeIntervalSeconds = (int)o.Probe.Interval.TotalSeconds,
             ProbeTimeoutSeconds = (int)o.Probe.Timeout.TotalSeconds,
@@ -181,6 +199,8 @@
             UseNativeNotifications = UseNativeNotifications,
             EnableControllerBrowse = EnableControllerBrowse,
             NotificationMaxDelayMs = NotificationMaxDelayMs,
+            UseSumRead = UseSumRead,
+            SumReadMaxItems = SumReadMaxItems,
             Probe = new TwinCATProbeOptions
             {
                 Enabled = ProbeEnabled,