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/ibm-cloud-subnets.svg

@@ -0,0 +1 @@
+<svg id="icon" width="32" height="32" viewBox="0 0 32 32"> <path class="cls-1" d="M26,22a3.6069,3.6069,0,0,0-2,.6L19.4143,18,18,19.4141,22.6,24a4.1755,4.1755,0,0,0-.4,1H9.8583A3.5525,3.5525,0,0,0,9.4,24L24,9.4a3.6069,3.6069,0,0,0,2,.6,4,4,0,1,0-3.8569-5H9.9A4.0785,4.0785,0,0,0,6,2a4,4,0,0,0,0,8,3.6066,3.6066,0,0,0,2-.6L12.5858,14,14,12.5859,9.4,8a4.175,4.175,0,0,0,.4-1H22.1418A3.5553,3.5553,0,0,0,22.6,8L8,22.6A3.6066,3.6066,0,0,0,6,22a4,4,0,1,0,3.8569,5H22.1A4.0118,4.0118,0,1,0,26,22ZM26,4a2,2,0,1,1-2,2A2.0058,2.0058,0,0,1,26,4ZM6,8A2,2,0,1,1,8,6,2.0058,2.0058,0,0,1,6,8ZM6,28a2,2,0,1,1,2-2A2.0058,2.0058,0,0,1,6,28Zm20,0a2,2,0,1,1,2-2A2.0058,2.0058,0,0,1,26,28Z" transform="translate(0 0)"/> </svg>