Animate two planets on Kepler orbits around a star in one self-contained HTML file

# Animate two planets on Kepler orbits around a star in one self-contained HTML file Make a small animated scene: a two-planet Kepler orbit. Write one file, `out/scene.html`, that works opened straight from disk with no network access. `spec.json` gives the page title, the stage size and the scene parameters. **Looks are not scored**: the page is opened in a headless browser (800x600 window, UTC time zone, network blocked) and checked by objective tests only. ## Scene contract - Draw the scene on one `<canvas>` or `<svg>` stage of `width` x `height` CSS pixels (spec.json), visible on load, with `<title>` containing spec.json `title`. - Animate continuously from load (`requestAnimationFrame` or timers); no click is needed unless stated below. - Expose `window.sceneState()`, returning the scene's current state in stage pixel coordinates (origin top-left of the stage): `{planets: [{name, x, y}, ...]} (canvas px, y down; names Inner and Outer)`. Extra fields are fine. It must describe what is actually drawn. - Time 0 is `performance.now()` 0 (seconds = `performance.now()` / 1000). Both planets start at periapsis. In each planet's orbit frame the position is (a(cos E − e), b sin E) with b = a√(1 − e²), mean anomaly 2πt/period = E − e sin E; rotate that frame by `periapsis_deg` counter-clockwise as seen on screen and place the focus on the star: x = star.x + X cos ω − Y sin ω, y = star.y − (X sin ω + Y cos ω). `sceneState()` must return the state at the moment it is called. - The page must log no errors and throw no exceptions. Keep the file at most 200,000 bytes; no external scripts, fonts, images or URLs (inline everything). ## Checks (partial credit = share passed) 1. `self_contained`: `out/scene.html` exists, is at most 200,000 bytes, references no http(s) or protocol-relative URL, and requests nothing from the network when opened. 2. `has_canvas_or_svg`: a visible `<canvas>` or `<svg>` of at least 300x200 CSS pixels is on the page. 3. `frames_change`: over 3 s, some later screenshot differs from the first in at least 0.1% of pixels, and at least 3 of 30 screenshots differ. 4. `kepler_position`: at every sample, Inner is within 1.5 px of its exact Kepler position: an ellipse with the star at one focus, semi-major axis `a_px`, eccentricity `e`, period `period_s`, at periapsis at time 0, moving by Kepler's equation. 5. `third_law_planet`: at every sample, Outer is within 1.5 px of its exact Kepler position, with its period from Kepler's third law (period² proportional to a³, scaled from Inner) since spec.json gives none. 6. `no_console_errors`: no uncaught exception, `console.error` or browser error is logged during the run. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.