docs: update README + docs site for public readiness

Refresh the README and documentation for public visitors:

- README: public-facing rewrite with accurate status for all four native
  clients (macOS, Linux, Windows, Android) and the Windows host.
- docs site: fix stale client status (Android is a full client, not a
  scaffold; Windows client is stage-1 complete + signed MSIX), add the
  missing Android client section, correct "which client" guidance.
- Windows host: corrected from "deferred/scoped" to implemented & shipping
  (NVIDIA-only, x64-only) across windows-host, roadmap, status,
  requirements, running-as-a-service, and the README.
- Remove internal infrastructure from public docs (box names, private IPs,
  SSH/token commands, deploy topology); rewrite status.md as a public
  project-status page; sanitize ci.md and implementation-plan.md.
- Update clients/android and clients/apple READMEs to current state.

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

docs-site/content/docs/install-client.md

@@ -85,8 +85,9 @@ certificate, so you import that certificate once before Windows will install the
 
 3. Launch **Punktfunk** from the Start menu and pick your host.
 
-> The Windows client is young (software decode; hardware D3D11VA/HDR in progress). If it
-> misbehaves, **[Moonlight](/docs/moonlight)** is a solid alternative for Windows.
+> The Windows client's hardware-decode (D3D11VA) and HDR paths are complete but still pending
+> validation on real GPU hardware. If anything misbehaves, **[Moonlight](/docs/moonlight)** is a
+> solid alternative for Windows.
 
 ## macOS