Automatic Source → MapLibre workflow

Deterministic, headless browser fixture for the golden automatic Source → MapLibre workflow (#390, AC#4 / Validation).

app.mjs drives a real MapLibre GL renderer and:

• explains the correct automatic strategy for every source shape — GeoJSON query, vector tiles, native raster tiles, WMS, WMTS, PMTiles (vector and raster), and dynamic query tiles;
• mounts the natively-understood tile strategies on the real renderer and disposes them cleanly (no leaked sources or layers);
• runs the incremental integration surface on the client-materialized geojson-query strategy via attachAutomaticMapLibreInteractions: selection (feature-state), a popup, a filter-registry-driven runtime filter (composed with the layer's baked-in geometry filter), realtime feature-state deltas, hit-testing, an in-place refresh, and leak-free disposal.

Feature data is served in-memory and native tile URLs point at the local fixture origin, so the fixture needs no external network.

The Playwright spec that serves and asserts against this fixture lives at test/playwright/automatic-source-workflow.spec.mjs and runs as part of npm run test:playwright.