Both panels now use position:fixed with JS-computed coordinates from
getBoundingClientRect(), ensuring they open directly below their
respective header buttons and right-aligned to the button edge.
History panel clamps left edge to prevent off-screen overflow.
Also adds missing click handlers for settings-btn and history-btn
in canvas.html (previously only wired in shell.ts module pages).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
fe7157ffe1