style: gofmt run

Re-runs gofmt over the four files lint flagged on PR: aligns struct
tag column widths in codebuff/session.go, openclaw/session.go,
qwen_cli/session.go and the table-test struct in codebuff/
chatid_test.go. No behaviour change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>