docs(pyrowave): document 4:4:4 + HDR and add an interactive bitrate calculator

- New "4:4:4 and HDR" section: what each mode buys, the ~1.6× / +15% bitrate
  cost, that HDR needs a Windows host today (Linux capture has no HDR source),
  and that the two combine (~1.9× the 4:2:0 SDR rate).
- Interactive <BitrateCalculator> (registered in the MDX components map):
  resolution (presets or custom), frame rate, 4:2:0/4:4:4, SDR/HDR -> the
  estimated Automatic pin, bits/pixel, per-frame size, and which link tier it
  needs. Formula mirrors the host's resolve_bitrate_kbps_for exactly.
- Expanded the bandwidth table with 120 Hz rows; note the big modes want 5/10 GbE.
- Document PUNKTFUNK_PYROWAVE_MAX_MBPS (cap the open-loop pin on a constrained
  link) in configuration.md.
- pyrowave.md -> .mdx so the page can host the component.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs-site/src/components/mdx.tsx

@@ -1,9 +1,12 @@
 import defaultMdxComponents from 'fumadocs-ui/mdx'
 import type { MDXComponents } from 'mdx/types'
+import BitrateCalculator from '@/components/BitrateCalculator'
 
 export function getMDXComponents(components?: MDXComponents) {
   return {
     ...defaultMdxComponents,
+    // Custom components usable in any .md/.mdx without a per-file import.
+    BitrateCalculator,
     ...components,
   } satisfies MDXComponents
 }