feat: v0.3.0 — flat 2D camera: remove zoom-driven tilt + terrain; max zoom ~100 km screen width

PLAN.md

@@ -1,7 +1,7 @@
 # Flight Ops — Game Design
 
 Browser game, pure economic gameplay: run a small airplane transport company in Europe.
-No manual flying — planes auto-fly assigned routes; you manage the business from an ops dashboard over a 2D map (lite 3D terrain if it stays lightweight).
+No manual flying — planes auto-fly assigned routes; you manage the business from an ops dashboard over a 2D map.
 
 ## Layout (single screen)
 - Left pane — Assets: fleet list (plane type, status, fuel, location), wallet, reputation
@@ -14,7 +14,7 @@ Accept job → dispatch a plane → watch it fly the route on the map → earn m
 ## Map & rendering
 - MapLibre GL JS with vector tiles (OpenFreeMap/OSM-based) — crisp detail down to ~10–100 m/px at city zoom, smooth continent overview; no Cesium needed
 - Camera: top-down when zoomed out, tilts to ~45° as you zoom in (zoom-driven pitch transition)
-- Lite 3D once tilted: terrain/hillshade from free DEM tiles + building extrusion if it stays lightweight, otherwise flat 2D
+- View is flat 2D only (zoom-driven tilt and terrain were removed in v0.3.0 as over-engineered)
 - Game-logic data (airports, runways, countries/regions): downloaded CSV dataset cached in `data/`
 
 ## Simulation engine