ci(ai-validation): address 3 follow-up CR/Copilot findings on validate-checkout step

After the first fix bundle landed on the three wave-5 PRs, three more
findings surfaced:

1. (CR on #1991, line 312) `rm -f` silently no-ops on directories. A
   fork could commit `changed-md.txt/`, `diff-md.patch/`, or
   `pass1-findings.json/` AS DIRECTORIES (not files), and the wipe
   step would skip them — the subsequent artifact-download writes
   into the real-file path would then collide with the fork-placed
   directory, producing unpredictable behaviour.

   Fix: use `rm -rf` for ALL reserved paths uniformly. The
   distinction was cosmetic at best; making it uniform closes the
   gap.

2. (Copilot on #1991, line 311) `.venv/` is also fork-attackable.
   `astral-sh/setup-uv` with `activate-environment: true` creates
   `${{ github.workspace }}/.venv` and prepends its `bin/` to PATH.
   If a fork pre-populates `.venv/bin/`, those binaries land in
   PATH for subsequent steps (Pass 1 runs `vyos-doc-review`, Pass 2
   runs `claude-code-action` whose internals may shell out).

   Fix: add `.venv` to the wipe list.

3. (Copilot on #1992, line 298) The inline comment block contains
   a literal `PR's` — a stray shell heredoc escape sequence
   that survived the commit verbatim. Confusing in YAML.

   Fix: replace with plain `PRs`.

Mirrored byte-identically across rolling/circinus/sagitta + canonical
follow-up after this wave merges.

0 files changed, 0 insertions, 0 deletions