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/flag.svg

@@ -0,0 +1 @@
+<svg id="icon" viewBox="0 0 32 32"><title>flag</title><path d="M6,30H4V2H28l-5.8,9L28,20H6ZM6,18H24.33L19.8,11l4.53-7H6Z"/></svg>