v0.20.19

Changed

• Design: two hardcoded color values in dashboard.css replaced with design tokens — drop-shadow(0 2px 4px rgba(0,0,0,0.15)) on .weather-widget__icon replaced with new --shadow-drop-icon token; rgba(0,0,0,0.25) on .fab-backdrop replaced with new --color-backdrop-fab token
• Design: --shadow-drop-icon and --color-backdrop-fab added to tokens.css (shadow and overlay sections respectively)