feat: canvas performance + cinematic upgrade

CHANGELOG.md

@@ -8,10 +8,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+
 - Initial project scaffold from [Studio51 Standards](https://github.com/studio51/standards).
+- Cinematic arrival (`intro`): ~3.2s choreographed bloom on load (nebula → stars → sphere → atmosphere → land → night/aurora/orbits → beams), with rotation easing in from stillness.
+- Six cinematic canvas layers: orbiting moon, rare comet, shimmering constellations, ocean sun glint, HQ heartbeat wave, and city surges.
+- New visual toggles: sun glare at the subsolar limb, in-canvas parallax starfield, nebula haze, and pointer parallax look-offset.
+- Fling inertia — flick the globe and it glides, decaying back into auto-rotation (works while paused).
+- Scene-schema `cinema` section and control-panel toggles for all the new options.
 
 ### Changed
 
+- Canvas renderer performance: zero trig in the hot loops (precomputed sin/cos with angle-sum projection), tier-sorted land dots drawn as contiguous runs, low-res offscreen terminator upscaled to screen, and cached GeoJSON rebuilt only when the sun moves.
+- Adaptive quality in `BaseEngine`: an EMA of frame time nudges a dpr multiplier (down to 0.55) with cooldown hysteresis so weak GPUs get a softer image instead of dropped frames.
+- Richer visuals: deeper offset-lit ocean, wider atmospheric rim with a crisp shell line, 4-layer beams, twin impact rings, 3-pass aurora, warmer city lights.
+- Calmer defaults and pacing: rotation 4°/s, activity 2.4/s, meteor frequency 40%, slower/longer-lived meteors and beams.
+
 ### Fixed
 
 [Unreleased]: https://github.com/studio51/orbit/commits/main