docs: scope Windows-as-host (deferred) + update roadmap status

A 4-agent read of the host crate: a Windows host is an "add a backend" job, not a parallel
port — ~95% reuse (core/protocol/FEC/crypto/C-ABI, QUIC, GameStream, mgmt, m3/pipeline are all
platform-agnostic and already cfg-isolated). New cfg(windows) backends behind the existing
traits: DXGI Desktop Duplication (capture), Media Foundation / NVENC-SDK (encode), SendInput +
ViGEm (input), WASAPI loopback + virtual mic (audio). The blocker is the virtual-display
feature — no user-mode Windows API; it needs a signed kernel-mode IDD driver (XL).

docs/windows-host.md records the per-subsystem effort + a phased plan (Phase 0 = a "basic
Windows host" capturing an existing monitor, smallest surface). Deferred: large and unbuildable
on the Linux dev box, per the request to only take it on if manageable. roadmap.md marks
#1/#2/#4 done, #3 packaged, and adds #7 Windows.

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

docs/roadmap.md

@@ -2,9 +2,14 @@
 
 Decided 2026-06-10 (research-grounded; see commit history). Sequence:
 **KDE reliability → client compositor options → mic passthrough → Bazzite COPR RPM (then
-bootc) → touch → full UHID DualSense → iOS.**
+bootc) → touch → full UHID DualSense → iOS** (+ Windows host, scoped & deferred).
 
-## 1. Reliable headless KDE/compositor spawning *(in progress)*
+**Done (2026-06-10):** #1 KDE reliability (Phase 1 + 2), #2 compositor options (full stack incl.
+macOS client), #4 mic passthrough — all on `main`, live-validated. #3 Bazzite packaging written
+(`packaging/`); the COPR/bootc build is operator-run. Remaining: #5 touch → UHID DualSense, #6 iOS,
+and a Windows host (`docs/windows-host.md`).
+
+## 1. Reliable headless KDE/compositor spawning ✅ *(done — Phase 1 + 2)*
 
 Startup is a chain of timing-sensitive handoffs with no readiness checks — each is a blind
 `sleep`, one-shot timeout, or silent fire-and-forget that fails into a black screen.
@@ -23,17 +28,21 @@ Startup is a chain of timing-sensitive handoffs with no readiness checks — eac
 - **Phase 3 (L):** supervised systemd user session (kwin + portal + host) with the readiness
   probe as an `ExecStartPost` gate, `Restart=on-failure`.
 
-## 2. Offer available compositors in the client *(M)*
+## 2. Offer available compositors in the client ✅ *(done)*
 
 Host enumerates which backends are actually available (binary present + version OK:
 gamescope ≥3.16.22, KWin ≥6.5.6, gnome-shell, sway), advertises the list in the punktfunk/1
 Welcome + a mgmt-API field; client sends its pick in the Hello; host honors it per session.
 Picker in the Apple client + web console.
 
-## 3. Bazzite / install on other devices *(decision: COPR RPM → bootc)*
+## 3. Bazzite / install on other devices ✅ *(packaging written — `packaging/`)*
 
 Bazzite already ships gamescope + PipeWire + the NVIDIA driver (incl. `libnvidia-encode`);
 it's Fedora-atomic and the community installs Sunshine via COPR rpm-ostree — the analog.
+Written: `packaging/rpm/punktfunk.spec` (builds the host from source), `packaging/bootc/Containerfile`
+(`FROM bazzite-nvidia`), `packaging/bazzite/host.env` (gamescope default), `packaging/copr/` +
+`packaging/README.md`. The build itself is operator-run (COPR / a Fedora toolbox; not buildable on
+the Ubuntu dev box). `LICENSE-{MIT,APACHE}` added to match the declared dual license.
 
 - **M-Bazzite-1:** a **COPR RPM** (primary) — binary + `60-punktfunk.rules` (→
   `/usr/lib/udev/rules.d`) + systemd `--user` unit + `host.env.example`; `Requires` the
@@ -45,7 +54,7 @@ it's Fedora-atomic and the community installs Sunshine via COPR rpm-ostree — t
 - Flatpak only later as an explicitly-degraded convenience build (sandbox fights
   zero-copy NVENC/dmabuf/uinput).
 
-## 4. Mic passthrough — client mic → host input device *(S+M)*
+## 4. Mic passthrough — client mic → host input device ✅ *(done — host side)*
 
 The exact mirror of the host→client desktop-audio path. A PipeWire virtual source apps can
 select = a `pw_stream` with `Direction::Output` + `media.class=Audio/Source`.
@@ -75,3 +84,15 @@ select = a `pw_stream` with `Direction::Output` + `media.class=Audio/Source`.
 
 PunktfunkKit is already platform-shared; iOS needs the `UIViewRepresentable` presenter twin
 + touch capture (#5) + UI. tvOS later.
+
+## 7. Windows as a host *(scoped & deferred — `docs/windows-host.md`)*
+
+Architecturally an "add a backend" job, not a parallel port: `punktfunk-core` (protocol/FEC/
+crypto/C-ABI) + QUIC + GameStream + mgmt + the `m3`/pipeline orchestration are all platform-agnostic
+and already `cfg`-isolated (~95% reuse). New `#[cfg(windows)]` backends behind the existing traits:
+capture (DXGI Desktop Duplication), encode (Media Foundation / NVENC-SDK with a D3D11 context),
+input (SendInput + ViGEm), audio (WASAPI loopback + a virtual mic). **The blocker** is the
+virtual-display feature — no user-mode Windows API; it needs a signed kernel-mode **IDD** driver
+(XL). Recommended start: **Phase 0** — a "basic Windows host" capturing an existing monitor (no
+virtual display), proving the whole stack with the smallest surface. Deferred because it's large and
+unbuildable on the Linux dev box; the trait boundaries are already in the right places.