Move the 'leave it out / multi-paragraph comments belong elsewhere'
clause ahead of the indent-examples bullet so the priority order reads
high-to-low, and point the off-source destinations at the real specs/
directory and README.md files instead of generic prose.
Move the duplicated doc-comment guidance out of go-code-style.md and
frontend-rules.md into .claude/rules/code-comments.md so both languages
share one source. Mirror the same block in AGENTS.md for Codex, which
does not load .claude/rules/. Raise the follow-up line cap from 1-2 to
up to 3 to match what compact comments actually need in practice.
