chore: track CLAUDE.md in git (was gitignored, now version-controlled)

CLAUDE.md was previously excluded from version control entirely (treated as
private local notes, with CLAUDE.example.md as the only git-tracked
counterpart). No longer justified - the file contains no secrets, just
architecture notes, private RFC1918 IPs, and operational lessons (same
sensitivity level as README.md, which is already tracked). Removing the
CLAUDE.md gitignore rule and committing it for the first time.

.gitignore

@@ -38,8 +38,9 @@ k8s/storage/test/test
 *.key
 *.conf
 
-# Allowed markdown: CLAUDE.example.md, README.md, TROUBLESHOOTING.md
-CLAUDE.md
+# CLAUDE.md is now version-controlled (was previously excluded as a
+# private-notes file; contains no secrets - just architecture, IPs
+# [private RFC1918 space], and operational lessons, same bar as README.md).
 
 # Terraform state and cache (local files, remote state in MinIO)
 .terraform/