fix(docker): re-add python3 to runtime image (regression of #161/#185) (#267)

PR #185 (commit 8b45b632) added python3 to the runtime Dockerfile to
fix issue #161 — terminal broken in Docker because scripts/pty-helper.py
requires Python at runtime.

Commit efcb7d14 (2026-05-01 'migrate legacy Hermes codename bytes to
canonical Claude') reverted the Dockerfile to a pre-#185 state without
python3, regressing #161 silently. Issue #259 reports the regression.

This is a one-line restore. Inline comment added so the next rename
sweep doesn't trip over it again.

Co-authored-by: Aurora release bot <release@outsourc-e.com>

Dockerfile

@@ -24,8 +24,11 @@ RUN pnpm build
 
 # ─── runtime stage ────────────────────────────────────────────────────────
 FROM node:22-slim
+# python3 is required by scripts/pty-helper.py (terminal feature). Originally
+# added in PR #185 for issue #161; regressed by the 2026-05-01 rename commit
+# efcb7d14 and re-added here per issue #259.
 RUN apt-get update && apt-get install -y --no-install-recommends \
-      ca-certificates curl tini \
+      ca-certificates curl tini python3 \
     && rm -rf /var/lib/apt/lists/* \
     && groupadd -r workspace && useradd -r -g workspace -u 10010 workspace