chore: bump version 02.30.00 → 02.31.00, cleanup legacy jmiller user

- Version bump across all manifests and docs
- Auto-cleanup of legacy master users no longer in MASTER_KEYS
- Updated CHANGELOG with all 02.31.00 changes

Authored-by: Moko Consulting
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/plugin-basic.md

@@ -11,12 +11,12 @@
  INGROUP: MokoWaaS
  REPO: https://github.com/mokoconsulting-tech/mokowaas
  PATH: /docs/plugin-basic.md
- VERSION: 02.30.00
+ VERSION: 02.31.00
  BRIEF: Baseline documentation for the MokoWaaS system plugin
  NOTE: Foundational reference for internal and external stakeholders
 -->
 
-# MokoWaaS Plugin Overview (VERSION: 02.30.00)
+# MokoWaaS Plugin Overview (VERSION: 02.31.00)
 
 ## Introduction