Embed the release version into the pipeline's output data, not just the log

[brawer]

Summary

The pipeline's release version (CARGO_PKG_VERSION) is currently only visible in the startup log record (src/logging.rs, "pipeline starting up, version=v{}"). It's not embedded anywhere in the pipeline's actual output -- the files clients download.

Now that Cargo.toml's version is kept authoritative and in sync with each release tag (scripts/cut-release.sh, see #562), and the CLI reports it via --version (#563), the version is trustworthy enough to be worth stamping into the product itself, not just the logs.

What to do

Embed the release version into the pipeline's output data, so a downstream consumer can tell which version of osm-diffs produced a given file without having to cross-reference log files or ask us. Exact mechanism TBD -- e.g. a metadata field/column in the output format(s), depending on what's feasible per output type.

Priority

Not urgent -- noting it down now so it doesn't get forgotten, per discussion while hardening the release process (#540 and follow-ups).

[brawer]

The main output is a Parquet file, so perhaps we can embed a JSON file (in CycloneDX 1.7 format) into the Parquet metadata, describing the data dependencies. For example, for the OpenStreetMap input, we could standard CycloneDX constructs to model the download url, OpenStreetMap changeset ID and timestamp; similar for all other inputs. Maybe this is a little over-engineered, but I think it's better to use an industry-standard format than to reinvent the wheel.