docs(historian): fix-wave docs and stale comments

- Historian.md: Empty samples always Bad (writer/updater/read clamp),
  long-name refusal, 5 s bootstrap failure cache, AtTime after now, info-bit
  masking, HistoryUpdate does NOT type-check (M-1 decision), DeleteRaw
  needs both bounds, reverse Raw paging, the historian/historization metric
  prefixes, and provisioning numeric-only lines qualified as Gateway.
- CLAUDE.md numeric-only lines qualified as Gateway backend.
- Stale 'sole historian' lines in DriverLifecycle, ServiceHosting and the
  retired Wonderware stub; Client.CLI exit-code contract.
- ServerHistorianOptions: Endpoint/Backend XML docs untangled, Validate()
  indented; Program.cs comments are backend-neutral; T10 week-test day count.

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

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Historian/ServerHistorianOptions.cs

@@ -4,12 +4,13 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Historian;
 
 /// <summary>
 ///     Binds the <c>ServerHistorian</c> configuration section that gates the server-side
-///     HistoryRead backend. When <see cref="Enabled"/> is <c>true</c>, <c>AddServerHistorian</c>
-///     registers a read-only <c>HistorianGateway</c>-backed <c>IHistorianDataSource</c> (supplied by
+///     historian. <see cref="Backend"/> selects the provider (<c>Gateway</c> by default, or <c>SqlServer</c>,
+///     whose own keys live in the <c>ServerHistorian:SqlServer</c> sub-section). When <see cref="Enabled"/> is
+///     <c>true</c>, <c>AddServerHistorian</c> registers that backend's <c>IHistorianDataSource</c> (supplied by
 ///     the Host) in place of the <c>NullHistorianDataSource</c> default; otherwise the Null default
 ///     survives and HistoryRead returns <c>GoodNoData</c>-empty.
 ///     <para>
-///         The read client talks gRPC to the <c>ZB.MOM.WW.HistorianGateway</c> sidecar
+///         On the Gateway backend the read client talks gRPC to the <c>ZB.MOM.WW.HistorianGateway</c> sidecar
 ///         (<c>historian_gateway.v1</c>) over <see cref="Endpoint"/>, authenticating with the
 ///         peppered-HMAC <see cref="ApiKey"/> (<c>histgw_&lt;id&gt;_&lt;secret&gt;</c>) in the
 ///         <c>Authorization: Bearer</c> header. This is the READ path only — there are no
@@ -24,17 +25,12 @@ public sealed class ServerHistorianOptions
     public const string SectionName = "ServerHistorian";
 
     /// <summary>
-    ///     When <c>true</c>, the HistorianGateway read client is registered as the
+    ///     When <c>true</c>, the selected backend's data source is registered as the
     ///     <c>IHistorianDataSource</c>; when <c>false</c> (the default) the no-op
     ///     <c>NullHistorianDataSource</c> stays in place and HistoryRead returns empty.
     /// </summary>
     public bool Enabled { get; init; }
 
-    /// <summary>
-    ///     Absolute gateway endpoint URI the read client dials (e.g. <c>https://host:5222</c>).
-    ///     The scheme selects the transport: <c>https://</c> = TLS, <c>http://</c> = h2c plaintext.
-    ///     Required when <see cref="Enabled"/> is <c>true</c>.
-    /// </summary>
     /// <summary>
     ///     Selects the historian backend provider (case-insensitive). Default <c>"Gateway"</c>; the Host's
     ///     <c>HistorianBackendRegistry</c> owns the set of valid names. Gateway-specific keys
@@ -49,6 +45,12 @@ public sealed class ServerHistorianOptions
     public bool IsGatewayBackend =>
         string.Equals(Backend?.Trim(), GatewayBackendName, StringComparison.OrdinalIgnoreCase);
 
+    /// <summary>
+    ///     Gateway backend only: absolute gateway endpoint URI the read client dials (e.g.
+    ///     <c>https://host:5222</c>). The scheme selects the transport: <c>https://</c> = TLS, <c>http://</c> = h2c
+    ///     plaintext. Required when the Gateway backend is consumed (<see cref="Enabled"/>, or an enabled
+    ///     <c>AlarmHistorian</c>).
+    /// </summary>
     public string Endpoint { get; init; } = "";
 
     /// <summary>
@@ -129,17 +131,17 @@ public sealed class ServerHistorianOptions
         // Gateway-specific checks apply only to the Gateway backend (other backends carry their own options).
         if (IsGatewayBackend)
         {
-        if (string.IsNullOrWhiteSpace(Endpoint))
-            warnings.Add("ServerHistorian:Endpoint is empty while the historian is enabled — the read client has no gateway address to dial.");
-        // archreview 06/S-11 warning parity: a non-empty but unparseable / non-absolute-http(s) Endpoint
-        // is just as fatal (it throws in the gateway client factory). Warn on it here so the Runtime-side
-        // registration logs describe malformed endpoints too, consistent with the Host's fail-fast
-        // ServerHistorianOptionsValidator (which turns this same condition into a startup failure).
-        else if (!Uri.TryCreate(Endpoint, UriKind.Absolute, out var uri)
-                 || (uri.Scheme != Uri.UriSchemeHttp && uri.Scheme != Uri.UriSchemeHttps))
-            warnings.Add($"ServerHistorian:Endpoint ('{Endpoint}') is not an absolute http(s) URI while the historian is enabled — the read client cannot dial it (e.g. https://host:5222).");
-        if (string.IsNullOrWhiteSpace(ApiKey))
-            warnings.Add("ServerHistorian:ApiKey is empty while the historian is enabled — the gateway gRPC surface will reject unauthenticated calls.");
+            if (string.IsNullOrWhiteSpace(Endpoint))
+                warnings.Add("ServerHistorian:Endpoint is empty while the historian is enabled — the read client has no gateway address to dial.");
+            // archreview 06/S-11 warning parity: a non-empty but unparseable / non-absolute-http(s) Endpoint
+            // is just as fatal (it throws in the gateway client factory). Warn on it here so the Runtime-side
+            // registration logs describe malformed endpoints too, consistent with the Host's fail-fast
+            // ServerHistorianOptionsValidator (which turns this same condition into a startup failure).
+            else if (!Uri.TryCreate(Endpoint, UriKind.Absolute, out var uri)
+                     || (uri.Scheme != Uri.UriSchemeHttp && uri.Scheme != Uri.UriSchemeHttps))
+                warnings.Add($"ServerHistorian:Endpoint ('{Endpoint}') is not an absolute http(s) URI while the historian is enabled — the read client cannot dial it (e.g. https://host:5222).");
+            if (string.IsNullOrWhiteSpace(ApiKey))
+                warnings.Add("ServerHistorian:ApiKey is empty while the historian is enabled — the gateway gRPC surface will reject unauthenticated calls.");
         }
         // MaxTieClusterOverfetch is intentionally checked AFTER the Enabled early-return above:
         // the over-fetch code path only runs when a real IHistorianDataSource is wired in,