wiki: add Carbon Design System icons (2673) + pictograms (1000)

- 2673 SVG icons from @carbon/icons v11.82.0 (~2.5 MB)
- 1000 SVG pictograms from Carbon Design System (~2.0 MB)
- Updated 00-overview.md with asset structure and category listing

All icons: 32x32, fill: currentColor, optimized SVG
All pictograms: 24x24, fill: currentColor, SVG

assets/icons/carbon/cU3.svg

@@ -0,0 +1 @@
+<svg id="icon" viewBox="0 0 32 32"><title>Q-research--cU3</title><path d="M10,23H5a2,2,0,0,1-2-2V15a2,2,0,0,1,2-2h5v2H5v6h5Z" transform="translate(0 0)"/><path d="M18,23H14a2,2,0,0,1-2-2V9h2V21h4V9h2V21A2,2,0,0,1,18,23Z" transform="translate(0 0)"/><path d="M28,9H22v2h6v4H23v2h5v4H22v2h6a2,2,0,0,0,2-2V11A2,2,0,0,0,28,9Z" transform="translate(0 0)"/></svg>