feat(clients/windows): single-window handoff, shared settings store, console-UI surfacing

UX polish batch 1 (clients/windows/ui-polish-plan.md, workstreams W0/A1/B/C/E):

- W0: the shell's duplicated trust/settings structs are gone — src/trust.rs
  re-exports pf-client-core's, so the shell and the spawned session binary share
  ONE Settings shape over client-windows-settings.json. Fixes real bugs: the
  shell's saves no longer drop session-side fields; the stats-overlay toggle
  (show_hud -> show_stats, serde alias migrates old files) and the forwarded-
  controller pick now actually reach the spawned session. The "Streaming engine"
  Settings combo is gone (PUNKTFUNK_BUILTIN_STREAM=1 stays as the dev A/B knob).

- Forwarded-controller pinning by stable key (vid:pid:name, pf-client-core's
  format): persisted as forward_pad, applied by the shell's own service at
  startup AND by the session binary in session_params (both OSes — the session
  never applied the pin before).

- A1 single window: the shell hides itself when the spawned session window
  presents its first frame ({"ready":true}) and restores + foregrounds on the
  child's exit — exactly one visible Punktfunk window at any time. Restore runs
  before the request-access cancel gate so a Ready/Cancel race can't strand the
  shell hidden.

- C console UI: punktfunk-session --browse gains --json-status (ready when the
  library window presents; error line on a failed start), and the shell
  surfaces it — "Open console UI" on paired hosts' menus, plus a controller-
  detected hint card targeting the most recent paired host (x64 only; aarch64
  ships no skia ui feature). Browse spawns hide/restore the shell like streams.

- B responsive: minimum window size (420x360); the hosts header collapses to
  icon-only buttons below 700 px; the session status card shrinks instead of
  clipping (max_width); busy pages, help actions, licenses and long labels wrap.

- E polish: session exe gets the app icon (winresource + WM_SETICON via the new
  pf-presenter win32.rs); both exes share an explicit AppUserModelID on
  unpackaged runs (packaged identity wins) so the windows group as one taskbar
  app across the visibility handoff; "Start streams fullscreen" toggle passes
  --fullscreen (GTK parity); connects stamp KnownHost::last_used; the connect
  target is stashed for every route so "Connecting to X" always names the host.

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

crates/pf-presenter/src/run.rs

@@ -226,6 +226,10 @@ impl StreamState {
 }
 
 fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>> {
+    // Before any window exists: unpackaged runs adopt the shell's AppUserModelID so the
+    // shell⇄session windows group as one taskbar app (win32.rs; MSIX identity wins).
+    #[cfg(windows)]
+    crate::win32::set_app_user_model_id();
     sdl3::hint::set("SDL_JOYSTICK_THREAD", "1");
     let sdl = sdl3::init().context("SDL init")?;
     let video = sdl.video().context("SDL video")?;
@@ -241,12 +245,22 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
         }
         b.build().context("SDL window")?
     };
+    // The exe-embedded icon onto the title bar/taskbar/Alt-Tab (SDL's class icon is the
+    // generic default); a no-op for exes that embed none.
+    #[cfg(windows)]
+    crate::win32::stamp_window_icon(&window);
     let instance_exts = window
         .vulkan_instance_extensions()
         .map_err(|e| anyhow::anyhow!("vulkan instance extensions: {e}"))?;
     let mut presenter = Presenter::new(&window, &instance_exts).context("vulkan presenter")?;
     // A valid black frame immediately — the window is honest while the connect runs.
     presenter.present(&window, FrameInput::Redraw, None)?;
+    // Browse mode is "ready" the moment the library window presents — there may never be
+    // a stream. (Single mode announces on the first VIDEO frame instead, further down, so
+    // a shell only yields to a window that actually shows the stream.)
+    if opts.json_status && matches!(mode, ModeCtl::Browse(_)) {
+        println!("{{\"ready\":true}}");
+    }
 
     let mut overlay = opts.overlay.take();
     if let Some(o) = overlay.as_mut() {