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/BPMN-conditional-fill.svg

@@ -0,0 +1,2 @@
+<svg id="Icon" width="32" height="32" viewBox="0 0 32 32"> <path d="M26,2H6c-.5522,0-1,.4478-1,1v26c0,.5522.4478,1,1,1h20c.5522,0,1-.4478,1-1V3c0-.5522-.4478-1-1-1ZM10,7h7v2h-7v-2ZM22,24h-12v-2h12v2ZM22,19h-12v-2h12v2ZM22,14h-12v-2h12v2Z"/>
+</svg>