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/contrast.svg

@@ -0,0 +1 @@
+<svg id="icon" viewBox="0 0 32 32"><title>contrast</title><path d="M29.37,11.84a13.6,13.6,0,0,0-1.06-2.51A14.17,14.17,0,0,0,25.9,6.1a14,14,0,1,0,0,19.8,14.17,14.17,0,0,0,2.41-3.23,13.6,13.6,0,0,0,1.06-2.51,14,14,0,0,0,0-8.32ZM4,16A12,12,0,0,1,16,4V28A12,12,0,0,1,4,16Z"/></svg>