docs(site): add Windows host install, restructure nav, new public roadmap

- install (host): add a Windows (NVIDIA) section with signed-installer and
  certificate-trust steps; note the .cer is the same across releases.
- install-client: clarify the Windows MSIX certificate is the same every
  release (trust once, updates need nothing).
- Move "Project & Internals" out of the public docs site: relocate
  implementation-plan, apple-stage2-presenter, gamescope-multiuser,
  dualsense-haptics, ci, and gamestream-host-plan to docs/; drop them from
  the nav. Move windows-host into Host Setup.
- Rewrite roadmap as a lean public page with an at-a-glance grid and
  current statuses (Windows host shipped/beta, Apple incl. tvOS shipped,
  Android shipped, concurrent sessions + delegated pairing done).
- Fix status.md link to the now-internal implementation plan.

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

docs/dualsense-haptics.md

@@ -1,4 +1,8 @@
-# DualSense advanced (audio-driven) haptics — feasibility & scoping
+---
+title: "DualSense Haptics"
+description: "Feasibility and scoping for audio-driven DualSense haptics."
+---
+
 
 **Status: scoped, NO-GO for now (deferred).** Advanced voice-coil haptics on the DualSense are
 driven by the controller's **USB audio interface** (4-channel surround, the back two channels carry