fix(security): land the 2026-07 audit fixes — SSRF guards, roster lane, SYSTEM path hygiene

The low/medium findings from the July host+Windows security review, as
implemented in the audit session's working tree:

- Webhooks and library-art fetches refuse loopback/link-local/metadata
  targets and no longer follow redirects (SSRF pivots from the privileged
  host process).
- The paired-client rosters (/clients, /native/clients) move off the
  streaming-client auth lane — one paired device could enumerate every other
  device's name + fingerprint; only the bearer/loopback console keeps them.
- Device-name sanitizing extends to bidi/format control characters
  (spoofable rendering) via the shared native_pairing::is_spoofy_char;
  stream-marker quoting uses the same set.
- The SYSTEM service resolves powershell by its full System32 path —
  CreateProcess checks the launching EXE's own directory first, so a planted
  powershell.exe beside the host binary would have run as SYSTEM.
- The pf-vdisplay driver's opt-in file log moves from world-writable
  C:\Users\Public to WUDFHost's own temp dir.
- GameStream pairing sessions are single-use (removed whatever the outcome).
- Uninstall also removes the pf_mouse driver-store entry (rider from the
  virtual-HID-mouse work).
- openapi.json regenerated (hardened-config-dir doc wording).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/punktfunk-host/src/mgmt/host.rs

@@ -306,8 +306,8 @@ pub(crate) async fn list_compositors() -> Json<Vec<AvailableCompositor>> {
 )]
 pub(crate) async fn get_status(State(st): State<Arc<MgmtState>>) -> Json<RuntimeStatus> {
     // GameStream plane (set by RTSP/nvhttp on the compat path).
-    let gs_launch = *st.app.launch.lock().unwrap();
-    let gs_stream = *st.app.stream.lock().unwrap();
+    let gs_launch = *st.app.launch.lock().unwrap_or_else(|e| e.into_inner());
+    let gs_stream = *st.app.stream.lock().unwrap_or_else(|e| e.into_inner());
     let gs_video = st.app.streaming.load(Ordering::SeqCst);
     let gs_audio = st.app.audio_streaming.load(Ordering::SeqCst);
     // Native punktfunk/1 plane (published by the native video loop; the default plane). See
@@ -362,7 +362,12 @@ pub(crate) async fn get_status(State(st): State<Arc<MgmtState>>) -> Json<Runtime
         video_streaming: gs_video || !native.is_empty(),
         audio_streaming: gs_audio || !native.is_empty(),
         pin_pending: st.app.pairing.pin.awaiting_pin(),
-        paired_clients: st.app.paired.lock().unwrap().len() as u32,
+        paired_clients: st
+            .app
+            .paired
+            .lock()
+            .unwrap_or_else(|e| e.into_inner())
+            .len() as u32,
         active_sessions: native.len() as u32 + u32::from(gs_video),
         session,
         stream,
@@ -417,7 +422,12 @@ pub(crate) async fn get_local_summary(State(st): State<Arc<MgmtState>>) -> Json<
         video_streaming: st.app.streaming.load(Ordering::SeqCst),
         audio_streaming: st.app.audio_streaming.load(Ordering::SeqCst),
         session,
-        paired_clients: st.app.paired.lock().unwrap().len() as u32,
+        paired_clients: st
+            .app
+            .paired
+            .lock()
+            .unwrap_or_else(|e| e.into_inner())
+            .len() as u32,
         native_paired_clients,
         pin_pending: st.app.pairing.pin.awaiting_pin(),
         pending_approvals,