Offer: help maintaining ClosedXML.Report

Hi @b0bi79, @Pankraty,

I'm Dimitrie. With a volunteer team I'm building **Rendlio**, a commercial XLSX→PDF rendering engine for .NET, and ClosedXML.Report is the template-filling library our own documentation recommends to users — so we have a direct, long-term interest in this project staying healthy. About us, up front: the engine will ship **source-available and free in production for anyone under $1M revenue** (every release becomes Apache-2.0 open source four years later); the larger companies that do pay fund charities, not shareholders — we're founding a Swiss association whose statutes pledge the profits to good causes. We mention it because it shapes how we behave in the ecosystem: upstream-first, credit where it's due.

We noticed recent releases are mostly compatibility bumps tracking ClosedXML core, and we'd like to help — under your direction, on your terms:

- triaging issues and reproducing bugs
- PRs for fixes and for compatibility with new ClosedXML releases
- extra testing: we run ClosedXML.Report output through our rendering QA pipeline, which catches template-engine edge cases early

If co-maintenance is more than you want, no hard feelings at all — we'll simply keep contributing ordinary PRs like any user. If it is welcome, tell us how you'd prefer to start (a first issue to take, your review rules — whatever suits you).

Thanks for the library.

— Dimitrie Vatra · hello@rendlio.com

No file, test, entry point, or concrete change is named in the offer. Start by asking the maintainers to nominate a first issue and explain their review expectations; the work is ready to begin only once a specific task and completion criteria are agreed.

Written by the indexing model from the issue text.