This reverts #1111 (3f3305cf). With the fingerprint stable, the ACPX engine
now resumes the previous Claude session, but the Claude transcript lives in
the per-run CLAUDE_CONFIG_DIR, which the server deletes after each run. acpx
uses resumePolicy same-session-only for persistent sessions, so the turn
fails ("Persistent ACP session ... could not be resumed: Resource not
found") instead of falling back to a fresh session (run 12a2a911).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>