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-security-groups.svg

@@ -0,0 +1,2 @@
+<svg id="icon" width="32" height="32" viewBox="0 0 32 32"> <path d="M22.86,25.86c-.72.75-1.54,1.42-2.46,1.94l-5.4,3.2-5.5-3.2c-3.4-2-5.5-5.6-5.5-9.5V4c0-1.1.9-2,2-2h18c1.1,0,2,.9,2,2v5h-2v-5H6v14.3c0,3.2,1.7,6.2,4.5,7.8l4.5,2.7,4.5-2.7c.73-.47,1.41-.99,2-1.6,0,0,1.36,1.36,1.36,1.36ZM28,12h-10v2h10v-2ZM28,20h-10v2h10v-2ZM30,16h-10v2h10v-2Z"/> <rect id="_x3C_Transparent_Rectangle_x3E_" class="cls-1" width="32" height="32"/>
+</svg>