Import active NaPTAN stops into a local SQLite spatial index, including conversion of British National Grid coordinates. Add local searches, shareable stop links, source details and transport mode colours while retaining OSM route lookup by ATCO code.
Closes#1
Flask is now declared under [project.optional-dependencies] as the
`web` extra, so `pip install osm-geojson[web]` installs both the CLI
and Flask. The `dev` extra includes Flask too so the test/dev venv
gets everything. Update README and AGENTS.md accordingly.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
