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.Commons/Messages/Management/TemplateCommands.cs

@@ -3,6 +3,13 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Management;
 public record ListTemplatesCommand;
 public record GetTemplateCommand(int TemplateId);
 public record CreateTemplateCommand(string Name, string? Description, int? ParentTemplateId);
+
+/// <summary>
+/// Updates a template. Optional fields use leave-unchanged semantics (followup #5):
+/// a <c>null</c> <see cref="Description"/> keeps the stored description (pass an empty
+/// string to clear it), and a <c>null</c> <see cref="ParentTemplateId"/> keeps the
+/// existing parent (the parent is immutable; a non-null value that differs is rejected).
+/// </summary>
 public record UpdateTemplateCommand(int TemplateId, string Name, string? Description, int? ParentTemplateId);
 public record DeleteTemplateCommand(int TemplateId);
 public record ValidateTemplateCommand(int TemplateId);