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/merge-node.svg

@@ -0,0 +1 @@
+<svg id="icon" width="32" height="32" viewBox="0 0 32 32"> <path class="cls-2" d="m28,20h-4l-8-8-8,8h-4c-1.1028,0-2,.8975-2,2v8h2v-8h4l8,8,8-8h4v8h2v-8c0-1.1025-.8972-2-2-2Zm-12,7.1714l-6.1714-6.1714,6.1714-6.1716,6.1714,6.1716-6.1714,6.1714Z"/> <polygon class="cls-2" points="11 7 16 12 21 7 19.5859 5.5859 17 8.1719 17 2 15 2 15 8.1719 12.4141 5.5859 11 7"/> </svg>