## Summary

This adds **Renovate** — an open-source tool that watches dependency
versions
and opens a pull request when a newer one is available — and points it
at the
LinkedIn build of Iceberg (`com.linkedin.iceberg`, the table library
OpenHouse
depends on). A scheduled job runs it every hour on GitHub's own
machines.

OpenHouse uses two versions of this library at the same time: one in the
`1.2.x` series (any version starting with `1.2.`) and one in the `1.5.x`
series. The tool keeps each series on its own newest version and never
lets one
cross into the other. First-run result, confirmed locally without
opening any
pull requests:

- `iceberg-core`: `1.2.0.17` → `1.2.0.18`
- `iceberg-core`: `1.5.2.11` → `1.5.2.15`

## Changes

- [x] New Features
- [x] Documentation

- `.github/renovate.json` — the rules above.
- `.github/workflows/renovate.yml` — the hourly scheduled job.
- `docs/development/renovate-iceberg-sync.md` — setup and reasoning.

## Testing Done

- [x] No tests added or updated.

Ran Renovate locally in a mode that reads the repo and looks up versions
but
opens no pull requests; it proposed exactly the two updates above, each
staying
inside its own series. Also checked `renovate.json` with Renovate's
official
config validator.

## Additional Information

- [ ] Breaking Changes
- [ ] Deprecations

**Optional:** adding a repository secret named `RENOVATE_TOKEN` lets the
update
pull requests run their tests automatically. GitHub will not start test
runs on
a pull request opened with a workflow's built-in credentials (a guard
against
workflows triggering each other), so without this secret the pull
requests
still open but you start their tests by hand. A personal access token or
a
GitHub App token works. It is not required to merge this change.

This covers the two main version numbers only. The separately pinned
`iceberg-aws` (`1.2.0.6`) is left out on purpose and can be added the
same way
later.