No hand-written SVG: visx charts, lucide icons, Mermaid journey diagram

- desktop: Growth chart, Health and portfolio sparklines and the rollout bar drawn with visx (responsive width,
  crosshair tooltip with real values, arrow keys, theme tokens, no animation); icons from lucide-react behind the
  existing Icon names; empty states are lucide icons on token tiles; store marks are generic lucide icons; stars are
  lucide; the brand mark moves to ui/brand.tsx as the one allowed inline SVG
- fixtures: app icons and store art stand-ins are PNGs rendered by tools/fixture-art.ts (lucide on gradients)
- site: icons are lucide's own files in site/img/icons (tools/site-icons.ts, with the ISC licence) shown as CSS masks;
  the journey diagram is rendered from docs/diagrams/journey.mmd by tools/diagrams.ts (Mermaid CLI), with a tall
  variant for phones
- tests/no-handmade-svg.test.ts fails on new inline SVG drawing in apps/desktop/src and site/*.html
- desktop bundle: 598.7 -> 695.5 kB minified, 174.6 -> 206.0 kB gzip

site/img/icons/play.svg

@@ -0,0 +1,15 @@
+<!-- @license lucide-static v1.55.0 - ISC -->
+<svg
+  class="lucide lucide-play"
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M5 5a2 2 0 0 1 3.008-1.728l11.997 6.998a2 2 0 0 1 .003 3.458l-12 7A2 2 0 0 1 5 19z" />
+</svg>