Invoke the validate-repo skill against the dbt project at ${DBT_PROJECT_DIR}.

This is an automated, unattended run. Do not ask any questions — in particular,
when the skill reaches its Phase C5 persistence step, do NOT ask whether to save
the report. Instead, write the final consolidated markdown report to exactly
this absolute path:

  ${REPORT_PATH}

Create any missing parent directories. After writing the report, print only the
single line:

DONE: ${REPORT_PATH}