Add Shan

**Font Project Git Repo URL:**

https://github.com/ShanFont/ShanFont

**Super short description of the Font Family:**

Shan is an open-source Unicode font family for the Shan (Tai) language, derived from Panglong Unicode and optimized for web and application use. It covers the Shan consonants, vowels, tone marks and digits of the Myanmar Unicode block (plus Khamti/Aiton extras from Myanmar Extended-A) and implements the `mym2` OpenType shaping model (ccmp/pres/blws/psts/blwf/pstf/pref/rphf/liga + mark/dist/kern). The family ships as 8 static styles — Thin, Regular, Bold, Black with matching Italics (STAT tables with wght/ital style linking) — and includes the full Google Fonts Latin Core glyphset (merged from Noto Sans, OFL). Editable UFO sources for all styles are in `sources/` and build deterministically with `gftools builder sources/config.yaml`. Font Bakery (`check-googlefonts`): 0 FAIL / 0 ERROR (report in `documentation/fontbakery-report.html`). Engineering and QA fixes for this submission were done with AI assistance; the letterforms derive from the human-designed Panglong Unicode.

**Requirements:**

By opening this issue, I confirm the project meets the following requirements:

- [x] The entire font project is available in a Github repository (repo) and licensed under the [OFL](https://openfontlicense.org/open-font-license-official-text/)
- [x] I confirm that by 'entire font project', no "plus" or "pro" or other larger version of the project exists as a retail font anywhere
- [x] The source files are available in the repo
- [x] I am the sole copyright author of the entire project, or all other copyright authors have licensed their work to me under the OFL, and I commit to clearly disclosing if AI tools were used in the creation of this project.
- [x] There are no "Reserved Font Names" in the OFL license information, or in the project documentation of any known upstream projects. If there are RFNs, they are not used in whole or in part in this family name, or, I want to discuss how Google can work with my use of them.
- [x] The family name is unique according to [namecheck.fontdata.com](https://namecheck.fontdata.com/)
- [x] The name of the font family expected to appear on app menus must be very clearly communicated and definitive. It should not include any copyright holder's full names or acronyms.
- [x] The font supports at least the Google Fonts 'Latin Core' glyphset from [github.com/googlefonts/glyphsets](https://github.com/googlefonts/glyphsets) ([direct link](https://github.com/googlefonts/glyphsets/blob/main/data/results/txt/nice-names/GF_Latin_Core.txt))
- [x] The repo has the [Google Fonts preferred upstream repo structure](https://googlefonts.github.io/gf-guide/upstream.html)
- [x] I have read, agree with, and comply with, the full [Google Fonts contributing requirements](https://googlefonts.github.io/gf-guide/index#pre-production-getting-your-fonts-ready-for-gf)
- [x] I will maintain the repository and participate in the onboarding process (addressing, solving, and responding to issues, merging pull requests, etc)

**Image:**


Start with the linked ShanFont repository, especially sources/config.yaml, and run the stated gftools builder command. Review documentation/fontbakery-report.html and the checked Google Fonts requirements; done means the font project is ready for the Google Fonts onboarding process and its submission details are accepted.

Written by the indexing model from the issue text.