deprecated note to use amount_raw

[ttboogie]

What

Add a deprecation note to the token_transfers_raw.amount column doc, steering readers to amount_raw.

Why

amount hardcodes a fixed 7-decimal scale (amount_raw * 0.0000001) in stellar-etl's token_transfer.go, regardless of the token's declared decimals, so it is wrong for any non-7-decimal token. The dbt layer already recomputes the correctly scaled amount from amount_raw downstream (int_token_transfer_enrichment), so marts are unaffected, but the amount_float doc block gave no warning. This adds the caveat so it shows in dbt docs.

Part of a set with stellar/stellar-etl-airflow#956 (BQ column description) and stellar/stellar-docs#2632 (public data dictionary).

Known limitations

Doc-only. The underlying scaling behavior in stellar-etl is not changed here.

PR Checklist

PR Structure

• This PR has reasonably narrow scope (if not, break it down into smaller PRs).
• This PR avoids mixing refactoring changes with feature changes (split into two PRs otherwise).
• This PR's title starts with the jira ticket associated with the PR.

Thoroughness

• This PR adds tests for the most critical parts of the new functionality or fixes.
• I've updated the docs and README with the added features, breaking changes, new instructions on how to use the repository.

Release planning

• I've decided if this PR requires a new major/minor/patch version accordingly to semver, and I've changed the name of the BRANCH to major/* , minor/* or patch/* .