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/content/docs/configuration.md

@@ -90,6 +90,7 @@ See your desktop page ([KDE](/docs/kde), [GNOME](/docs/gnome)) for when to set t
 | `PUNKTFUNK_FEC_PCT` | `N` (percent) | Forward-error-correction redundancy for lossy links (the default is sensible for a normal LAN). Higher = more loss-resilient, more bandwidth. |
 | `PUNKTFUNK_10BIT` | `1` · `0` *(default on)* | HEVC Main10 / HDR. **On by default** — the host permits 10-bit; a session goes 10-bit only when the client advertises it (behind the client's HDR setting). Set `0` to force 8-bit. **Windows host only** (the Linux host stays 8-bit). |
 | `PUNKTFUNK_444` | `1` · `0` *(default on)* | Full-chroma HEVC 4:4:4 (Range Extensions) — sharper text/desktop, no chroma loss. **On by default** on the host; the client's own 4:4:4 setting (default off) is the real switch. Set `0` to force 4:2:0. **punktfunk/1 native only** (Moonlight stays 4:2:0), HEVC-only, honored only when the client advertises 4:4:4 **and** the GPU supports it (probed; NVENC is the validated path — VAAPI/AMF/QSV decline). Independent of 10-bit. |
+| `PUNKTFUNK_PYROWAVE_MAX_MBPS` | `N` (Mbps) | Cap the [PyroWave](/docs/pyrowave) Automatic bitrate pin, for a host on a link that the open-loop pin can outrun (e.g. 4:4:4 + HDR at 5120×1440@240 pins ~5.3 Gbps, over a 5GbE link). Unset = no cap. Only affects Automatic (bitrate `0`) PyroWave sessions; an explicit client bitrate bypasses it. |
 | `PUNKTFUNK_DSCP` | `1` | Opt-in DSCP / `SO_PRIORITY` QoS tagging on the media sockets. No-op on the wire on Windows without a qWAVE policy. |
 | `PUNKTFUNK_OH264_THREADS` / `PUNKTFUNK_OH264_GOP` | `N` | Software (openh264) encoder tuning: encode threads (default 2 — latency over throughput) and GOP length (default 0 = encoder-auto). Only relevant with `PUNKTFUNK_ENCODER=software`. |