docs(github-ops): Add hard rule — no local-machine paths in committed content

New Hard Rule #7 in SKILL.md: never bake user-specific or
ephemeral filesystem paths (C:\Users\<name>\..., /home/<name>/...,
/tmp/<one-off>) into README, Recent Updates, CHANGELOG, release
notes, tag annotations, or commit messages.

Public release artefacts have to read the same on someone else's
machine. Use generic placeholders or describe the file's purpose
abstractly. Canonical project paths (install locations, config
paths) state them canonically ($HOME/.claude/...) rather than as
literal absolutes with embedded user names.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>