[Feature] Support changelog production

Search before asking

• I searched in the issues and found nothing similar.

Motivation

Java Paimon supports producing changelog files for primary-key tables through the
changelog-producer option, including input, lookup, and full-compaction
modes.

Paimon C++ already contains part of the required infrastructure, such as:

• Parsing the changelog-producer option.
• Changelog file metadata in DataIncrement and CompactIncrement.
• Changelog manifest and snapshot commit support.
• Lookup changelog merge functions and changelog compaction rewriters.
• Streaming changelog scans and the audit_log and binlog system tables.

However, schema validation currently rejects every value except none, and the
writer does not produce changelog files. As a result, primary-key tables written
by Paimon C++ cannot provide the same changelog behavior as tables written by
Java Paimon.

Supporting Java-compatible changelog production would enable incremental
downstream consumption and improve interoperability between Java Paimon and
Paimon C++.

Solution

Implement changelog production for Paimon C++ primary-key table writes, aligned
with Java Paimon semantics and storage format.

The implementation should cover the following producer modes:

• input

  • Preserve input row kinds and double-write input changes to changelog files.
  • Attach generated changelog files to the corresponding data increment.

• lookup

  • Look up the previous value of each primary key when necessary.
  • Produce the correct INSERT, UPDATE_BEFORE, UPDATE_AFTER, and DELETE
    records.
  • Generate changelog files while compacting level-0 data.

• full-compaction

  • Produce changelog files during full compaction by comparing the compacted
    result with the previous table state.

The generated changelog files should:

• Use the same file schema, row-kind encoding, metadata, and directory layout as
  Java Paimon.
• Be committed through changelog manifests and referenced by the snapshot.
• Be readable through streaming scans, audit_log, and binlog.
• Work correctly with supported merge engines, sequence fields, partitions, and
  bucket modes.
• Either support deletion vectors consistently with Java Paimon or reject
  unsupported combinations with a clear validation error.
• Be included in commit metrics, expiration, rollback, and orphan-file cleanup.

The feature can be delivered incrementally, with separate pull requests for each
changelog producer mode.

Anything else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!