Mermaid 0.1.0 engineering twin

Recovered Bangel/MJos sources are included unchanged at revision
229548f13a4856455b3d30d408cf845fb5b557fc. Source ownership and notices are
retained in the downloadable source bundle. Mermaid extensions are identified
separately in source-lock.json.

Pyodide 0.29.5: https://github.com/pyodide/pyodide
Mozilla Public License 2.0. The Pyodide loader and runtime are served locally.
CPython 3.13.2: Python Software Foundation License.
https://docs.python.org/3/license.html
SQLite: public domain, https://www.sqlite.org/copyright.html
Package/version digests are retained with Mermaid's release evidence.