docs: fill missing XML docs and strip tracking IDs from src comments

Clears CommentChecker findings in src/ (3,280 -> 209, the remainder being false
positives like PLC-5/IEEE-754/M0.0) by adding missing summaries/params/returns,
normalising inheritdoc usage, and removing Gitea/review tracking IDs while keeping
the rationale they annotated. Comment-only: comment-stripped sources are identical
to the parent commit.

src/Server/ZB.MOM.WW.OtOpcUa.Security/ServiceCollectionExtensions.cs

@@ -65,7 +65,7 @@ public static class ServiceCollectionExtensions
 
         // Shared ZB.MOM.WW.Auth group→role mapper seam. Wraps the existing RoleMapper.Map +
         // RoleMapper.Merge logic; consumed by AuthEndpoints.cs (/auth/login) and by
-        // AdminUI login (the OPC UA data plane uses API keys since #520). Scoped to match
+        // AdminUI login (the OPC UA data plane uses API keys). Scoped to match
         // ILdapGroupRoleMappingService (DbContext-backed, registered Scoped) — a singleton here
         // would capture the scoped DB service.
         services.TryAddScoped<IGroupRoleMapper<string>, OtOpcUaGroupRoleMapper>();