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/chat.svg

@@ -0,0 +1 @@
+<svg id="icon" viewBox="0 0 32 32"><title>chat</title><path d="M17.74,30,16,29l4-7h6a2,2,0,0,0,2-2V8a2,2,0,0,0-2-2H6A2,2,0,0,0,4,8V20a2,2,0,0,0,2,2h9v2H6a4,4,0,0,1-4-4V8A4,4,0,0,1,6,4H26a4,4,0,0,1,4,4V20a4,4,0,0,1-4,4H21.16Z" transform="translate(0 0)"/><rect x="8" y="10" width="16" height="2"/><rect x="8" y="16" width="10" height="2"/></svg>