YachtMemory - Stay Processing Phase 1C.1e-a2
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Purpose:
Add enrichment_input_revision to stay_processing so a later worker can distinguish
a retry/processing state for the SAME input revision from a genuinely NEW Stay revision.

This phase does NOT change StayProcessingWriter.php or worker behavior.

Migration behavior:
1. Adds nullable enrichment_input_revision.
2. Initializes it only for COMPLETE Enrichment rows whose persisted
   stay_enrichment.stay_revision demonstrably equals stays.revision.
3. Does not alter status fields or attempt/retry metadata.

Important:
- Run the SQL migration ONCE.
- Do not rerun earlier 1C.1e-a migrations.
- SilentMessDB is not touched.
- The verifier is READ ONLY.

From /var/www/app.yachtmemory.net:

  cat database/migrations/05_stay_processing_enrichment_input_revision.sql

  php -l shared_dashboard/scripts/verify_stay_processing_input_revision.php

  mysql -u admin -p yachtmemory_derived \
    < database/migrations/05_stay_processing_enrichment_input_revision.sql

  php shared_dashboard/scripts/verify_stay_processing_input_revision.php

Expected current baseline:
- 36 processing rows.
- no NULL/invalid/mismatching enrichment_input_revision.
- #1-35 normally revision 1.
- #36 was revision 3 at the last controlled validation; if the Stay has been
  deliberately reprocessed since then, the verifier checks consistency rather
  than hard-coding revision 3.
- all Enrichment statuses remain COMPLETE.
- Geography, Classification and Overall remain PENDING.
- all phase-specific attempt/retry metadata remains zero/NULL.