release: v5.12.1 — "Footgun guard" (Pattern H live-session caveat)

Version-sync for the Pattern H recommendation fix shipped in 45efed3:
- plugin.json 5.12.0 -> 5.12.1
- README version badge + version-history row (1297 tests)
- CHANGELOG [5.12.1] entry

Recommendation string only — no new finding ID or scanner (count stays 16,
agents 7, commands 21), no token figures changed, so --json/--raw stay
byte-stable and frozen v5.0.0 + SC-5 + default-output snapshots are untouched.

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

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "config-audit",
   "description": "Multi-agent workflow for analyzing, reporting, and optimizing Claude Code configuration across your entire machine",
-  "version": "5.12.0",
+  "version": "5.12.1",
   "author": {
     "name": "Kjell Tore Guttormsen"
   },