feat(cli+templateengine+deploymanager): resolve follow-ups #4/#5/#6/#8 — CLI ergonomics + structured deploy validation error

Closes the four remaining items in the 2026-06-24 template-inheritance/CLI
follow-up tracker.

#4 — CLI `instance set-bindings` can now set DataSourceReferenceOverride.
  `--bindings` accepts an optional 3rd element per entry:
  [attributeName, dataConnectionId, dataSourceReferenceOverride]. A string
  sets the override; a JSON null or an omitted 3rd element leaves it unset
  (template default). TryParseBindings accepts 2- or 3-element entries and
  rejects a non-string/non-null 3rd element or 4+ elements with a clean
  error. Previously the CLI sent the override as null and silently wiped any
  existing one (only a raw POST /management could set it).

#5 — `template update` is partial, not full-replace (fixed server-side so all
  clients benefit). UpdateTemplateAsync now uses leave-unchanged semantics:
  a null description keeps the stored value (pass "" to clear); a null
  parentTemplateId keeps the existing parent. Parent stays immutable — a
  non-null differing value is still rejected — but omitting --parent-id is
  now a no-op instead of failing every derived-template update.

#6 — compact `template list`/`get` table output + `--detail`. Table output is
  now id/name/description/parent/derived + member counts (#attrs/#alarms/
  #scripts/#comps/#nativeAlarms) via TemplateTableProjection, fed through a
  new optional tableProjector seam on CommandHelpers. `--detail` restores the
  full dump. JSON output is left untouched (always full) so machine consumers
  are unaffected — the projector only runs on the table path.

#8 — structured deploy-time validation error. New ValidationResult.SummarizeErrors()
  (Commons) returns a grouped, capped summary: leading total count, one line
  per ValidationCategory, and a per-module rollup (canonical name up to its
  last dot) with counts + "... and N more module(s)" caps. DeploymentService
  uses it for the "Pre-deployment validation failed" message and logs the full
  per-entry list via LogWarning. Replaces the flat semicolon-joined dump that
  became a wall of text for instances with 50-194 unbound attributes.

Tests: +8 Commons (SummarizeErrors), +8 CLI (4 binding 3-element / 4 table
projection), +2 net TemplateEngine (partial-update). Affected suites green:
Commons 587, CLI 341, TemplateEngine 447, DeploymentManager 101,
ManagementService 230, CentralUI 866; full solution builds 0/0.

Docs: Component-DeploymentManager.md "Validation Error Reporting"; CLI README
(set-bindings 3-element form, template update leave-unchanged, list/get
--detail); UpdateTemplateCommand doc; known-issues tracker #4/#5/#6/#8 resolved
(all 8 items now closed).

src/ZB.MOM.WW.ScadaBridge.CLI/Commands/InstanceCommands.cs

@@ -54,7 +54,18 @@ public static class InstanceCommands
     private static Command BuildSetBindings(Option<string> urlOption, Option<string> formatOption, Option<string> usernameOption, Option<string> passwordOption)
     {
         var idOption = new Option<int>("--id") { Description = "Instance ID", Required = true };
-        var bindingsOption = new Option<string>("--bindings") { Description = "JSON array of [attributeName, dataConnectionId] pairs", Required = true };
+        var bindingsOption = new Option<string>("--bindings")
+        {
+            Description = "JSON array of binding entries. Each entry is either " +
+                          "[attributeName, dataConnectionId] or " +
+                          "[attributeName, dataConnectionId, dataSourceReferenceOverride] " +
+                          "(the 3rd element overrides the attribute's data-source reference; " +
+                          "pass null or omit it to use the template default). " +
+                          "NOTE: this REPLACES all bindings for the instance — include the " +
+                          "override on every entry that needs one, or omitting it clears any " +
+                          "previously-set override.",
+            Required = true
+        };
 
         var cmd = new Command("set-bindings") { Description = "Set data connection bindings for an instance" };
         cmd.Add(idOption);
@@ -76,11 +87,16 @@ public static class InstanceCommands
     }
 
     /// <summary>
-    /// Parses the <c>--bindings</c> argument — a JSON array of
-    /// <c>[attributeName, dataConnectionId]</c> pairs — into a typed list.
-    /// Returns <c>false</c> with a descriptive <paramref name="error"/> instead of
-    /// throwing when the JSON is malformed, a pair has the wrong arity, or an element
-    /// has the wrong type.
+    /// Parses the <c>--bindings</c> argument — a JSON array of binding entries — into a
+    /// typed list. Each entry is either a two-element
+    /// <c>[attributeName, dataConnectionId]</c> pair or a three-element
+    /// <c>[attributeName, dataConnectionId, dataSourceReferenceOverride]</c> triple. The
+    /// optional third element carries the per-instance data-source reference override
+    /// (<see cref="ConnectionBinding.DataSourceReferenceOverride"/>); a JSON
+    /// <c>null</c> (or an omitted third element) leaves it unset so the template default
+    /// applies. Returns <c>false</c> with a descriptive <paramref name="error"/> instead
+    /// of throwing when the JSON is malformed, an entry has the wrong arity, or an
+    /// element has the wrong type.
     /// </summary>
     /// <param name="json">The JSON string to parse.</param>
     /// <param name="bindings">The parsed bindings list, or null if parsing fails.</param>
@@ -99,16 +115,19 @@ public static class InstanceCommands
                 .Deserialize<List<List<System.Text.Json.JsonElement>>>(json);
             if (pairs == null)
             {
-                error = "Bindings JSON must be a non-null array of [attributeName, dataConnectionId] pairs.";
+                error = "Bindings JSON must be a non-null array of "
+                    + "[attributeName, dataConnectionId] or "
+                    + "[attributeName, dataConnectionId, dataSourceReferenceOverride] entries.";
                 return false;
             }
 
             var result = new List<ConnectionBinding>(pairs.Count);
             foreach (var pair in pairs)
             {
-                if (pair.Count != 2)
+                if (pair.Count is not (2 or 3))
                 {
-                    error = "Each binding must be a [attributeName, dataConnectionId] pair of exactly two elements.";
+                    error = "Each binding must be a [attributeName, dataConnectionId] pair, "
+                        + "optionally with a third dataSourceReferenceOverride element.";
                     return false;
                 }
                 if (pair[0].ValueKind != System.Text.Json.JsonValueKind.String)
@@ -122,7 +141,24 @@ public static class InstanceCommands
                     error = "The second element of each binding (dataConnectionId) must be an integer.";
                     return false;
                 }
-                result.Add(new ConnectionBinding(pair[0].GetString()!, connectionId));
+
+                string? referenceOverride = null;
+                if (pair.Count == 3)
+                {
+                    var third = pair[2];
+                    if (third.ValueKind == System.Text.Json.JsonValueKind.String)
+                    {
+                        referenceOverride = third.GetString();
+                    }
+                    else if (third.ValueKind != System.Text.Json.JsonValueKind.Null)
+                    {
+                        error = "The third element of each binding (dataSourceReferenceOverride) "
+                            + "must be a string or null.";
+                        return false;
+                    }
+                }
+
+                result.Add(new ConnectionBinding(pair[0].GetString()!, connectionId, referenceOverride));
             }
 
             bindings = result;