docs: complete XML doc coverage (returns, summaries, inheritdoc)

Resolve all 622 issues flagged by the enhanced CommentChecker: add missing
<returns> tags (incl. the standard phrasing on non-generic Task methods),
add missing <summary> tags, and replace misused/redundant <inheritdoc/> on
members that override or implement nothing with real documentation.
Documentation-only — no behavior change; solution builds clean.

src/ZB.MOM.WW.ScadaBridge.TemplateEngine/LockEnforcer.cs

@@ -27,6 +27,7 @@ public static class LockEnforcer
     /// </summary>
     /// <param name="original">The parent template's attribute definition.</param>
     /// <param name="proposed">The child template's proposed override.</param>
+    /// <returns>An error message string if a rule is violated; <c>null</c> if the override is permitted.</returns>
     public static string? ValidateAttributeOverride(
         TemplateAttribute original,
         TemplateAttribute proposed)
@@ -56,6 +57,7 @@ public static class LockEnforcer
     /// </summary>
     /// <param name="original">The parent template's alarm definition.</param>
     /// <param name="proposed">The child template's proposed override.</param>
+    /// <returns>An error message string if a rule is violated; <c>null</c> if the override is permitted.</returns>
     public static string? ValidateAlarmOverride(
         TemplateAlarm original,
         TemplateAlarm proposed)
@@ -85,6 +87,7 @@ public static class LockEnforcer
     /// </summary>
     /// <param name="original">The parent template's script definition.</param>
     /// <param name="proposed">The child template's proposed override.</param>
+    /// <returns>An error message string if a rule is violated; <c>null</c> if the override is permitted.</returns>
     public static string? ValidateScriptOverride(
         TemplateScript original,
         TemplateScript proposed)
@@ -110,6 +113,7 @@ public static class LockEnforcer
     /// <param name="originalIsLocked">The current lock state of the member.</param>
     /// <param name="proposedIsLocked">The proposed lock state.</param>
     /// <param name="memberName">Name of the member being changed, for error messages.</param>
+    /// <returns>An error message if unlocking is attempted; <c>null</c> if the lock change is valid.</returns>
     public static string? ValidateLockChange(bool originalIsLocked, bool proposedIsLocked, string memberName)
     {
         if (originalIsLocked && !proposedIsLocked)
@@ -130,6 +134,7 @@ public static class LockEnforcer
     /// <param name="originalLockedInDerived">Current <c>LockedInDerived</c> state.</param>
     /// <param name="proposedLockedInDerived">Proposed <c>LockedInDerived</c> state.</param>
     /// <param name="memberName">Name of the member being changed, for error messages.</param>
+    /// <returns>An error message if the locked-in-derived flag is being cleared; <c>null</c> if the change is valid.</returns>
     public static string? ValidateLockedInDerivedChange(
         bool originalLockedInDerived,
         bool proposedLockedInDerived,