chore(claude): deny gofmt in Claude Code permissions

Repo mandates gofumpt, not gofmt (CLAUDE.md, .golangci.yml). Denying the
raw command prevents Claude Code from running gofmt directly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: osterman

.claude/settings.json

@@ -39,6 +39,7 @@
       "Bash(git reset --hard:*)",
       "Bash(git clean:*)",
       "Bash(go clean:*)",
+      "Bash(gofmt:*)",
       "Bash(git add -A:*)",
       "Bash(git add --all:*)",
       "Bash(git add .:*)",