Use rule-name alias in inline disable directives

Reference link-fragments instead of MD051 in the markdownlint-disable
comments, matching the config style.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: sir-sigurd

OPERATIONS.md

@@ -21,15 +21,15 @@ This document provides comprehensive operational procedures for cloud teams mana
 - [ ] Backup verification (10 min) - [Instructions](#backup-verification-10-minutes)
 - [ ] Security updates (15 min) - [Instructions](#security-updates-15-minutes)
 <!-- TODO: no "Capacity review" section exists yet; see https://github.com/quiltdata/iac/issues/95 -->
-<!-- markdownlint-disable-next-line MD051 -->
+<!-- markdownlint-disable-next-line link-fragments -->
 - [ ] Capacity review (10 min) - [Instructions](#capacity-monitoring)
 
 ### Monthly Checklist
 
 - [ ] Capacity planning (20 min) - [Instructions](#capacity-planning-20-minutes)
 - [ ] Cost review (15 min) - [Instructions](#cost-optimization-recommendations)
 <!-- TODO: no "Security audit" section exists yet; see https://github.com/quiltdata/iac/issues/95 -->
-<!-- markdownlint-disable-next-line MD051 -->
+<!-- markdownlint-disable-next-line link-fragments -->
 - [ ] Security audit (30 min) - [Instructions](#security-audit)
 
 ## Installation Procedures