fix(plugin-security): remove the docblock fragment the merge resolution left

A stray block-comment opener and two leftover closing braces from the
retired anchor gate sat after extractSingleId's docblock; the opener
swallowed the braces up to the next docblock.

Claude-Session: https://claude.ai/code/session_01KppP2MoD91F3pXiXXrAmcF
Co-Authored-By: Claude <noreply@anthropic.com>

Author: claude

packages/plugins/plugin-security/src/security-plugin.ts

@@ -6750,10 +6750,6 @@ export class SecurityPlugin implements Plugin {
    * multi-row predicate and returns `null` (multi-row writes route through the
    * `*Many` paths, out of scope for the by-id pre-image check).
    */
-  /**
-    }
-  }
-
   /**
    * [commit 6feac910b] Does this object declare that its access — writes included — derives
    * from a master record (ADR-0055 `controlled_by_parent`)?