docs(src): add missing XML docs and strip tracking-ID comments

Sweep of 203 source files resolving CommentChecker findings: add
<summary>/<param>/<returns>/<inheritdoc> where missing, and remove
resolved task/issue tracking markers (Tests-NNN, Worker-NNN, Server-NNN,
Task N) from code comments. Comment/doc-only — no logic changes.
Server+Tests build clean under TreatWarningsAsErrors.

src/ZB.MOM.WW.MxGateway.Tests/Alarms/GatewayAlarmMonitorProviderModeTests.cs

@@ -24,6 +24,8 @@ public sealed class GatewayAlarmMonitorProviderModeTests
 {
     private static readonly TimeSpan WaitTimeout = TimeSpan.FromSeconds(15);
 
+    /// <summary>A worker-reported provider-mode change to subtag broadcasts a degraded status message and increments the provider-switch metric.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ProviderModeChange_BroadcastsDegradedStatus_AndIncrementsSwitchMetric()
     {
@@ -121,12 +123,13 @@ public sealed class GatewayAlarmMonitorProviderModeTests
     }
 
     /// <summary>
-    ///     Server-053: a redundant <c>OnAlarmProviderModeChanged</c> event whose target
+    ///     A redundant <c>OnAlarmProviderModeChanged</c> event whose target
     ///     mode equals the current mode still records a provider switch. The worker is the
     ///     authority on when a mode change occurred; the gateway does not second-guess it,
     ///     so each event the worker emits increments <c>provider_switches</c> (no from==to
     ///     suppression). This test pins that semantics so it cannot drift silently.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ProviderModeChange_RepeatedSameMode_RecordsASwitchForEachEvent()
     {
@@ -219,7 +222,7 @@ public sealed class GatewayAlarmMonitorProviderModeTests
     }
 
     /// <summary>
-    ///     Tests-032: pins the monitor's <c>toMode → AlarmProviderSwitchReason</c>
+    ///     Pins the monitor's <c>toMode → AlarmProviderSwitchReason</c>
     ///     derivation (<c>GatewayAlarmMonitor.ApplyProviderModeChangeAsync</c>): an
     ///     alarmmgr→subtag change must emit <c>reason=failover</c> and a subtag→alarmmgr
     ///     change must emit <c>reason=failback</c>. Captures the <c>reason</c> tag off the
@@ -227,6 +230,7 @@ public sealed class GatewayAlarmMonitorProviderModeTests
     ///     the Failover/Failback arms or collapsed them to Unknown would be caught here,
     ///     whereas the count-only tests above would still pass.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ProviderModeChange_FailoverThenFailback_RecordsCorrectReasonTags()
     {
@@ -338,6 +342,8 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         await monitor.StopAsync(CancellationToken.None);
     }
 
+    /// <summary>A subscriber that joins the alarm feed receives the current provider status as its first message.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task NewSubscriber_ReceivesProviderStatusAsFirstMessage()
     {
@@ -374,6 +380,8 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         await monitor.StopAsync(CancellationToken.None);
     }
 
+    /// <summary>With the fallback mode forced to subtag, the initial provider status baselines to degraded subtag without recording a provider switch.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ForceSubtagConfig_BaselinesProviderStatusToSubtagDegraded_WithoutSwitch()
     {
@@ -448,6 +456,8 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         await monitor.StopAsync(CancellationToken.None);
     }
 
+    /// <summary>With the fallback mode forced to alarm manager, the initial provider status baselines to non-degraded alarmmgr without recording a provider switch.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ForceAlarmManagerConfig_BaselinesProviderStatusToAlarmmgr_WithoutSwitch()
     {
@@ -519,6 +529,8 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         await monitor.StopAsync(CancellationToken.None);
     }
 
+    /// <summary>The monitor's SubscribeAlarms command carries the forced provider mode, failover settings, and watch list resolved from configuration.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SubscribeAlarms_SendsForcedModeAndWatchList_FromConfiguration()
     {
@@ -565,6 +577,10 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         await monitor.StopAsync(CancellationToken.None);
     }
 
+    /// <summary>The configured fallback mode string maps to the expected <see cref="AlarmProviderMode"/> sent in the SubscribeAlarms command.</summary>
+    /// <param name="mode">The configured fallback mode string.</param>
+    /// <param name="expected">The expected forced <see cref="AlarmProviderMode"/>.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Theory]
     [InlineData("ForceAlarmManager", AlarmProviderMode.Alarmmgr)]
     [InlineData("forcealarmmanager", AlarmProviderMode.Alarmmgr)]
@@ -701,10 +717,13 @@ public sealed class GatewayAlarmMonitorProviderModeTests
         public SubscribeAlarmsCommand? LastSubscribeCommand { get; private set; }
 
         /// <summary>Pushes a worker event onto the monitor's event stream.</summary>
+        /// <param name="mxEvent">The worker event to push.</param>
         public void EmitEvent(MxEvent mxEvent) =>
             _events.Writer.TryWrite(new WorkerEvent { Event = mxEvent });
 
         /// <summary>Completes once the monitor has issued its SubscribeAlarms command.</summary>
+        /// <param name="timeout">The maximum time to wait.</param>
+        /// <returns>A task that represents the asynchronous operation.</returns>
         public Task WaitForSubscribeAsync(TimeSpan timeout) => _subscribed.Task.WaitAsync(timeout);
 
         /// <inheritdoc />