Cardano Updates

CRON_TZ is silently ignored on the dune host; entries fire in server
local time. Document the conversion and the DST drift, and mention it
in the bootstrap step so a new operator edits the times for their
server's timezone.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Debian's cron silently ignores CRON_TZ=UTC on some installs. Verified
on dune (Europe/Zurich): entries with non-zero minutes never fire when
CRON_TZ is set, while \"0 \" entries fire at LOCAL even hours (which
look correct only because *2 lines up cleanly with the 2h tz offset).

Switch to local CEST times (04:00 CEST = 02:00 UTC) and document the
DST behaviour. The retry polling absorbs the 1h drift during CET.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Dune is in CEST (UTC+2). Without CRON_TZ, an entry like "0 2 * * *"
fires at 02:00 CEST = 00:00 UTC — two hours before yaci-store writes
the new daily parquet at 02:00 UTC, causing the retry loop to
exhaust before files arrive.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

- Document EXPORT_DATA_PATH, SKIP_PG_VALIDATION, TELEGRAM/SLACK env vars
- Add Deployment section: cron schedule, daily-pipeline.sh steps,
  CloudFront manifest, and update-code.sh for git-less servers
- Update exporter count (12 -> 13 with adapot) and rename
  contract_registry -> smart_contract_registry throughout
- fetched_at is timestamp(us, tz=UTC), not string
- Add source_data_watermark column to external_exporter_runs schema
- Document --validate-adapot CLI flag
- External/hybrid output writes to EXPORT_DATA_PATH (falls back to
  BASE_DATA_PATH)

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Servers without PG access (e.g., dune which has data via sshfs but no
local Postgres) can set SKIP_PG_VALIDATION=true in .env to skip
parquet vs PG row count validation. Also fixed trap message that
hardcoded "UAT" — now uses PROJECT_DIR/logs.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>