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/chart-treemap.svg

@@ -0,0 +1 @@
+<svg id="icon" width="32" height="32" viewBox="0 0 32 32"> <title>chart--treemap</title> <path d="M28,2H4A2.0023,2.0023,0,0,0,2,4V28a2.0023,2.0023,0,0,0,2,2H28a2.0023,2.0023,0,0,0,2-2V4A2.0023,2.0023,0,0,0,28,2Zm0,12H23V4h5ZM16,4h5V14H16ZM14,4V20H4V4ZM4,22H14v6H4Zm12,6V16H28V28Z"/> </svg>