[codex] Create `codex` module folder and move `codex.symlink` into it

[0xdevalias]

Goal

Reorganize the codex files so that codex.symlink lives inside a dedicated dotfiles module folder (codex/), keeping runtime payload separate from dotfiles tooling and docs.

Current Layout

• codex.symlink/ is at the repo root.
• This means any supporting scripts or notes would end up inside ~/.codex if placed alongside the symlink.

Proposed Layout

• Create a codex/ folder at the top level (the codex module).
• Move the existing tree into codex/codex.symlink/ unchanged.
• Future helpers (install.sh, notes, etc.) will live inside codex/ but outside codex.symlink, so they don’t get linked into ~/.codex.

Manual Relink Steps

• Move the folder:
  mkdir -p ~/.dotfiles/codex && mv ~/.dotfiles/codex.symlink ~/.dotfiles/codex/
• Update the home symlink if it already exists:

  if [ -L ~/.codex ]; then
    ln -sn ~/.dotfiles/codex/codex.symlink ~/.codex
  else
    echo "~/.codex isn’t a symlink; handle manually."
  fi

• Verify with: ls -la ~/.codex
• Commit the move: git add codex && git commit -m "Refactor: move codex.symlink into codex module"

Other Considerations

• Ensure .gitignore inside codex/codex.symlink/ still excludes runtime artefacts (sessions/, log/, etc.).
• Update any docs or scripts referencing codex.symlink/... to point to codex/codex.symlink/....
• On other machines: delete or update ~/.codex after pulling the change.

See Also

• [script] bootstrap: Add Scoped Link Mode to Bootstrap's install_dotfiles #38