Atlas is now a plain library plus a tiny web app with no framework:

- p3k\Atlas\App routes the seven endpoints, p3k\Atlas\View renders the
  plain PHP templates, p3k\Atlas\Response carries the result. Controllers
  are ported line for line from the Slim closures.
- p3k\geo\StaticMap\render() returns the image bytes and content type
  instead of sending headers and echoing, so other apps can embed it.
  generate() remains as a wrapper. The tile size constant is namespaced.
- Fix Airports::from_code() (the file handle was never kept) and the
  reference to a Geocoder class that never existed.
- composer: type library, PHP 8.1+, ext-gd required; lib/helpers.php is no
  longer autoloaded so nothing global leaks into consumers.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LeX8DR83QNwGUBJDAXj8fi

closes #11

for #8

for #9

for #9

for #9

(seems to be different between imagemagick 3.3.0 and 3.4.3)

was previously sometimes one zoom level too far

add bezier parameter which takes an angle used to draw bezier curves between points when drawing line segments

closes #2