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).

tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Types/ValidationResultSummaryTests.cs

@@ -0,0 +1,111 @@
+using ZB.MOM.WW.ScadaBridge.Commons.Types.Flattening;
+
+namespace ZB.MOM.WW.ScadaBridge.Commons.Tests.Types;
+
+/// <summary>
+/// Tests for <see cref="ValidationResult.SummarizeErrors"/> (followup #8) — the grouped,
+/// capped summary that replaces the flat semicolon-joined deploy error dump.
+/// </summary>
+public class ValidationResultSummaryTests
+{
+    private static ValidationEntry Unbound(string canonicalName) =>
+        ValidationEntry.Error(
+            ValidationCategory.ConnectionBinding,
+            $"Attribute '{canonicalName}' has a data source reference but no connection binding.",
+            canonicalName);
+
+    [Fact]
+    public void SummarizeErrors_NoErrors_ReturnsEmpty()
+    {
+        Assert.Equal(string.Empty, ValidationResult.Success().SummarizeErrors());
+    }
+
+    [Fact]
+    public void SummarizeErrors_LeadsWithTotalCount()
+    {
+        var result = new ValidationResult
+        {
+            Errors = [Unbound("A.X"), Unbound("A.Y"), Unbound("B.Z")]
+        };
+
+        var summary = result.SummarizeErrors();
+
+        Assert.StartsWith("3 errors:", summary);
+    }
+
+    [Fact]
+    public void SummarizeErrors_SingleError_UsesSingularNoun()
+    {
+        var result = new ValidationResult { Errors = [Unbound("A.X")] };
+        Assert.StartsWith("1 error:", result.SummarizeErrors());
+    }
+
+    [Fact]
+    public void SummarizeErrors_RollsUpUnboundAttributesByModuleWithCounts()
+    {
+        // 12 + 12 unbound across two LeakTest modules — the reported wall-of-text case.
+        var errors = new List<ValidationEntry>();
+        for (var i = 0; i < 12; i++) errors.Add(Unbound($"LeftReactorSide.LeakTest.Attr{i}"));
+        for (var i = 0; i < 12; i++) errors.Add(Unbound($"RightReactorSide.LeakTest.Attr{i}"));
+
+        var summary = new ValidationResult { Errors = errors }.SummarizeErrors();
+
+        Assert.Contains("24 errors:", summary);
+        Assert.Contains("ConnectionBinding (24)", summary);
+        Assert.Contains("LeftReactorSide.LeakTest (12)", summary);
+        Assert.Contains("RightReactorSide.LeakTest (12)", summary);
+        // The full 24 individual clauses must NOT all appear inline.
+        Assert.DoesNotContain("Attr11' has a data source reference", summary);
+    }
+
+    [Fact]
+    public void SummarizeErrors_CapsModuleBreadthWithAndNMore()
+    {
+        // 10 distinct modules, cap at 3 → 7 collapsed.
+        var errors = Enumerable.Range(0, 10).Select(i => Unbound($"Module{i}.Attr")).ToList();
+
+        var summary = new ValidationResult { Errors = errors }.SummarizeErrors(maxGroups: 3);
+
+        Assert.Contains("… and 7 more module(s)", summary);
+        Assert.Contains("Module0 (1)", summary);
+    }
+
+    [Fact]
+    public void SummarizeErrors_TopLevelMember_GroupsUnderRoot()
+    {
+        var summary = new ValidationResult { Errors = [Unbound("Speed")] }.SummarizeErrors();
+        Assert.Contains("(root) (1)", summary);
+    }
+
+    [Fact]
+    public void SummarizeErrors_EntriesWithoutEntityName_FallBackToCappedMessageList()
+    {
+        var errors = Enumerable.Range(0, 5)
+            .Select(i => ValidationEntry.Error(ValidationCategory.ScriptCompilation, $"compile error {i}"))
+            .ToList();
+
+        var summary = new ValidationResult { Errors = errors }.SummarizeErrors(maxGroups: 2);
+
+        Assert.Contains("ScriptCompilation (5)", summary);
+        Assert.Contains("compile error 0", summary);
+        Assert.Contains("… and 3 more", summary);
+    }
+
+    [Fact]
+    public void SummarizeErrors_MixedCategories_ListsEachCategoryGroup()
+    {
+        var result = new ValidationResult
+        {
+            Errors =
+            [
+                Unbound("A.X"),
+                ValidationEntry.Error(ValidationCategory.NamingCollision, "dup name 'Foo'"),
+            ]
+        };
+
+        var summary = result.SummarizeErrors();
+
+        Assert.Contains("ConnectionBinding (1)", summary);
+        Assert.Contains("NamingCollision (1)", summary);
+    }
+}