feat(clients/windows): game library page + session window placement + help polish

UX polish batch 2 (plan workstreams D/E5/E6):

- D: a mouse/keyboard game library page over pf-client-core::library (the GTK
  ui_library.rs counterpart): responsive 2-6 column poster grid (2:3 portraits,
  store badge, monogram placeholder while art streams in), loading / error+retry
  / empty / grid states, tap-to-play via a normal spawn carrying --launch id.
  Poster bytes land in a disk cache (%LOCALAPPDATA%\punktfunk\art-cache) so the
  Image widget loads file:/// URIs (reactor has no from-bytes source) and
  revisits render instantly. Reached from a paired host's "Browse library..."
  menu item behind the new "Show game library (experimental)" Settings toggle
  (the shared library_enabled field, Apple/GTK parity). A Shared::library_gen
  generation guard keeps a superseded fetch from publishing (speed-test pattern).

- E5: the session window opens at the shell's own top-left (--window-pos, new
  SessionOpts::window_pos) instead of centered on the primary display - streams
  land on the monitor the shell is on, and the hide/restore handoff reads as one
  window changing content. Fullscreen follows that display.

- E6: the Help shortcuts add Alt+Enter and the controller escape chord
  (LB+RB+Start+Back, hold to disconnect).

Also: rustfmt normalization of the merged probe helper.

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

clients/session/src/browse.rs

@@ -8,7 +8,9 @@
 //! pair-first scene. `PUNKTFUNK_FAKE_LIBRARY=<file.json>` feeds canned entries with no
 //! host (portrait paths starting with `/` load from disk), the GPU-only dev path.
 
-use crate::session_main::{arg_flag, arg_value, fullscreen_mode, parse_host_port, session_params};
+use crate::session_main::{
+    arg_flag, arg_value, fullscreen_mode, parse_host_port, session_params, window_pos,
+};
 use pf_client_core::{library, trust};
 use pf_console_ui::{LibraryGame, LibraryPhase, LibraryShared, SkiaOverlay};
 use pf_presenter::overlay::OverlayAction;
@@ -61,6 +63,7 @@ pub fn run(target: &str) -> u8 {
     let opts = pf_presenter::SessionOpts {
         window_title: format!("Punktfunk · {host_label}"),
         fullscreen: fullscreen_mode(),
+        window_pos: window_pos(),
         print_stats: settings.show_stats || arg_flag("--stats"),
         json_status,
         on_connected: Some(Box::new(|fingerprint: [u8; 32]| {

clients/session/src/main.rs

@@ -52,6 +52,15 @@ mod session_main {
             || std::env::var_os("GAMESCOPE_WAYLAND_DISPLAY").is_some()
     }
 
+    /// `--window-pos X,Y` → the window's top-left in desktop coordinates (a spawning
+    /// shell passes its own position so the session opens on the same monitor); absent or
+    /// unparsable = centered on the primary display.
+    pub(crate) fn window_pos() -> Option<(i32, i32)> {
+        let v = arg_value("--window-pos")?;
+        let (x, y) = v.split_once(',')?;
+        Some((x.trim().parse().ok()?, y.trim().parse().ok()?))
+    }
+
     /// `host[:port]`, port defaulting to the native 9777.
     pub(crate) fn parse_host_port(target: &str) -> (String, u16) {
         match target.rsplit_once(':') {
@@ -308,6 +317,7 @@ mod session_main {
         let opts = pf_presenter::SessionOpts {
             window_title: format!("Punktfunk · {title}"),
             fullscreen,
+            window_pos: window_pos(),
             print_stats: settings.show_stats || arg_flag("--stats"),
             json_status: true,
             on_connected: Some(Box::new(|fingerprint: [u8; 32]| {

clients/windows/src/app/connect.rs

@@ -79,6 +79,44 @@ fn initiate_opts(
     }
 }
 
+/// Start a stream that launches a library title on connect (`--launch id`) — the library
+/// page's tap-to-play. The library only opens for paired hosts, so the pin resolves like
+/// a normal initiate; a host forgotten mid-visit routes to the PIN ceremony instead.
+pub(crate) fn initiate_launch(
+    ctx: &Arc<AppCtx>,
+    target: Target,
+    launch: String,
+    set_screen: &AsyncSetState<Screen>,
+    set_status: &AsyncSetState<String>,
+) {
+    *ctx.shared.target.lock().unwrap() = target.clone();
+    let known = KnownHosts::load();
+    let pin = target
+        .fp_hex
+        .as_deref()
+        .and_then(trust::parse_hex32)
+        .or_else(|| {
+            known
+                .find_by_addr(&target.addr, target.port)
+                .and_then(|k| trust::parse_hex32(&k.fp_hex))
+        });
+    let Some(pin) = pin else {
+        set_screen.call(Screen::Pair);
+        return;
+    };
+    connect_with(
+        ctx,
+        &target,
+        Some(pin),
+        set_screen,
+        set_status,
+        ConnectOpts {
+            launch: Some(launch),
+            ..ConnectOpts::default()
+        },
+    );
+}
+
 /// The mode to request: explicit settings, with `0` fields resolved to the native size/refresh
 /// of the display our window is on (mirrors the Linux/Swift clients' native-display default).
 pub(crate) fn resolve_mode(s: &Settings) -> Mode {
@@ -181,6 +219,11 @@ pub(crate) struct ConnectOpts {
     /// failure escalates to the visible "Waking…" wait. The wait's own redial clears the flag,
     /// so it can't loop.
     wake_on_fail: bool,
+    /// A library title id (`steam:570`, …) the host launches during the connect handshake —
+    /// the library page's tap-to-play. Spawn mode passes it as `--launch`; the legacy
+    /// in-process path has no launch plumbing (it predates the library and is slated for
+    /// deletion).
+    launch: Option<String>,
 }
 
 impl Default for ConnectOpts {
@@ -191,6 +234,7 @@ impl Default for ConnectOpts {
             awaiting_approval: false,
             cancel: None,
             wake_on_fail: false,
+            launch: None,
         }
     }
 }
@@ -396,7 +440,7 @@ fn connect_spawn(
         &fp_arg,
         opts.connect_timeout.as_secs(),
         fullscreen,
-        None,
+        opts.launch.as_deref(),
         child,
         move |event| {
             use crate::spawn::SpawnEvent;
@@ -544,7 +588,7 @@ pub(crate) fn request_access(props: &Svc, target: &Target) {
             persist_paired: true,
             awaiting_approval: true,
             cancel: Some(cancel),
-            wake_on_fail: false,
+            ..ConnectOpts::default()
         },
     );
 }

clients/windows/src/app/help.rs

@@ -8,15 +8,21 @@ use super::Screen;
 use windows_reactor::*;
 
 /// The in-stream keyboard shortcuts, in the GTK Shortcuts window's order: the chord, then what it
-/// does. Read-only — the bindings themselves live in the input hook ([`crate::input`]).
+/// does. Read-only — the keyboard bindings live in the session window (`pf-presenter`'s run
+/// loop; the legacy builtin path's in [`crate::input`]), the controller chord in its gamepad
+/// service.
 const STREAM_SHORTCUTS: &[(&str, &str)] = &[
-    ("F11", "Toggle fullscreen"),
+    ("F11 / Alt+Enter", "Toggle fullscreen"),
     (
         "Ctrl+Alt+Shift+Q",
         "Release captured input (click the stream to recapture)",
     ),
     ("Ctrl+Alt+Shift+D", "Disconnect"),
     ("Ctrl+Alt+Shift+S", "Toggle the statistics overlay"),
+    (
+        "LB+RB+Start+Back",
+        "Controller: release input / leave fullscreen \u{2014} hold to disconnect",
+    ),
 ];
 
 /// A subtle key-cap chip for the shortcuts reference — the chord on a filled, bordered pill.

clients/windows/src/app/hosts.rs

@@ -13,6 +13,7 @@ use windows_reactor::*;
 
 /// Overflow-menu item labels — `on_item_clicked` reports the clicked item by its text.
 const MENU_CONNECT: &str = "Connect";
+const MENU_LIBRARY: &str = "Browse library\u{2026}";
 const MENU_CONSOLE: &str = "Open console UI";
 const MENU_SPEED: &str = "Test network speed\u{2026}";
 const MENU_WAKE: &str = "Wake host";
@@ -186,22 +187,6 @@ fn status_row(online: Option<bool>, badge: &str, kind: Pill) -> Element {
         .into()
 }
 
-/// Lay tiles into a `cols`-wide grid of equal-width star columns (rows share the height of
-/// their tallest tile, so a grid row always lines up).
-fn tile_grid(tiles: Vec<Element>, cols: usize) -> Element {
-    let rows = tiles.len().div_ceil(cols);
-    let mut children = Vec::with_capacity(tiles.len());
-    for (i, t) in tiles.into_iter().enumerate() {
-        children.push(t.grid_row((i / cols) as i32).grid_column((i % cols) as i32));
-    }
-    grid(children)
-        .columns(vec![GridLength::Star(1.0); cols])
-        .rows(vec![GridLength::Auto; rows])
-        .column_spacing(TILE_GAP)
-        .row_spacing(TILE_GAP)
-        .into()
-}
-
 /// The in-tile rename editor (ContentDialog can't hold a text field): name box + save/cancel.
 /// No tap-to-connect while editing — a click into the box would bubble `Tapped` to the region.
 fn rename_editor(
@@ -269,6 +254,8 @@ pub(crate) fn hosts_page(props: &HostsProps, cx: &mut RenderCx) -> Element {
         set: props.set_hover.clone(),
     };
     let known = KnownHosts::load();
+    // The experimental library gate ("Show game library" in Settings) — GTK/Apple parity.
+    let library_enabled = ctx.settings.lock().unwrap().library_enabled;
 
     // Responsive column count from the live window width (re-renders on resize): as many
     // TILE_MIN_WIDTH columns as fit the page's content width, at least one.
@@ -445,8 +432,13 @@ pub(crate) fn hosts_page(props: &HostsProps, cx: &mut RenderCx) -> Element {
                     .automation_name("More options")
                     .menu_flyout({
                         let mut items = vec![menu_item(MENU_CONNECT)];
-                        // The gamepad library — paired hosts only (the mgmt API needs the
+                        // The library surfaces — mouse/KB page and the gamepad console UI —
-                        // paired identity) and only where the session ships the console UI.
+                        // for paired hosts only (the mgmt API needs the paired identity);
+                        // the page additionally sits behind the experimental toggle, the
+                        // console UI behind the x64-only skia build.
+                        if library_enabled && k.paired {
+                            items.push(menu_item(MENU_LIBRARY));
+                        }
                         if CONSOLE_UI_AVAILABLE && k.paired {
                             items.push(menu_item(MENU_CONSOLE));
                         }
@@ -464,6 +456,11 @@ pub(crate) fn hosts_page(props: &HostsProps, cx: &mut RenderCx) -> Element {
                         MENU_CONNECT => {
                             initiate(&svc.ctx, target.clone(), &svc.set_screen, &svc.set_status)
                         }
+                        MENU_LIBRARY => {
+                            *svc.ctx.shared.target.lock().unwrap() = target.clone();
+                            super::library::start_fetch(&svc.ctx, &svc.set_library);
+                            svc.set_screen.call(Screen::Library);
+                        }
                         MENU_CONSOLE => {
                             open_console(&svc.ctx, target.clone(), &svc.set_screen, &svc.set_status)
                         }
@@ -508,7 +505,7 @@ pub(crate) fn hosts_page(props: &HostsProps, cx: &mut RenderCx) -> Element {
                 })),
             ));
         }
-        body.push(tile_grid(tiles, cols));
+        body.push(tile_grid(tiles, cols, TILE_GAP));
     }
 
     // Discovered hosts not already saved above.
@@ -560,7 +557,7 @@ pub(crate) fn hosts_page(props: &HostsProps, cx: &mut RenderCx) -> Element {
                 Some(Box::new(move || initiate(&ctx2, target.clone(), &ss, &st))),
             ));
         }
-        body.push(tile_grid(tiles, cols));
+        body.push(tile_grid(tiles, cols, TILE_GAP));
     }
 
     // Forget confirmation (modal; shown while `forget` holds a pending host). Confirmed first,

clients/windows/src/app/library.rs

@@ -0,0 +1,355 @@
+//! The game library page (mouse/keyboard): the target host's library as a responsive
+//! poster grid over `pf-client-core::library` — the WinUI counterpart of the GTK shell's
+//! `ui_library.rs`, sharing its service layer (mTLS fetch against the host's management
+//! API, pre-classified errors, the 3-worker art pipeline) and its four states
+//! (loading / error+retry / empty / grid). Reached from a paired host's "…" menu
+//! ("Browse library…", behind the Settings "Show game library" experimental toggle);
+//! picking a title starts a normal stream carrying `--launch id` — the host launches the
+//! app during the connect handshake.
+//!
+//! Poster bytes land in a small disk cache (`%LOCALAPPDATA%\punktfunk\art-cache`) and the
+//! `Image` widget loads `file:///` URIs from it — reactor's `ImageSource` has no
+//! from-bytes constructor, and the cache makes revisits (and offline browsing) instant.
+//!
+//! Re-render discipline: the fetch and the art stream complete on worker threads, so the
+//! whole [`LibraryState`] lives in ROOT state (see the app module docs) and arrives here
+//! as a prop; `Shared::library_gen` invalidates a superseded fetch exactly like the
+//! speed test's generation guard.
+
+use super::connect::initiate_launch;
+use super::style::*;
+use super::{AppCtx, Screen, Svc};
+use pf_client_core::library;
+use std::collections::{HashMap, VecDeque};
+use std::path::{Path, PathBuf};
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+use windows_reactor::*;
+
+/// Poster-grid metrics: minimum poster-column width before dropping a column, the gap,
+/// and the 2:3 portrait ratio.
+const POSTER_MIN_WIDTH: f64 = 150.0;
+const POSTER_GAP: f64 = 12.0;
+const POSTER_RATIO: f64 = 1.5;
+
+/// One game, as the grid renders it (the wire `GameEntry` minus the artwork paths, which
+/// resolve into `LibraryState::art`).
+#[derive(Clone, PartialEq)]
+pub(crate) struct Game {
+    pub(crate) id: String,
+    pub(crate) title: String,
+    pub(crate) store: String,
+}
+
+#[derive(Clone, PartialEq, Default)]
+pub(crate) enum LibraryPhase {
+    #[default]
+    Loading,
+    Failed(String),
+    Empty,
+    Ready(Vec<Game>),
+}
+
+/// The page's whole thread-driven state: the fetch phase plus poster art as it lands
+/// (game id → `file:///` URI into the disk cache).
+#[derive(Clone, PartialEq, Default)]
+pub(crate) struct LibraryState {
+    pub(crate) phase: LibraryPhase,
+    pub(crate) art: HashMap<String, String>,
+}
+
+/// Props for the library page: the services plus the fetch/art state driving re-render.
+#[derive(Clone)]
+pub(crate) struct LibraryProps {
+    pub(crate) svc: Svc,
+    pub(crate) state: LibraryState,
+}
+
+impl PartialEq for LibraryProps {
+    fn eq(&self, other: &Self) -> bool {
+        self.svc == other.svc && self.state == other.state
+    }
+}
+
+/// Fetch the library for `Shared::target` off the UI thread, publishing into root state:
+/// phase first, then art entries as the workers stream them in. A newer call (re-open,
+/// Retry, another host) bumps `Shared::library_gen`, and a superseded worker stops
+/// publishing — the speed test's generation pattern.
+pub(crate) fn start_fetch(ctx: &Arc<AppCtx>, set_library: &AsyncSetState<LibraryState>) {
+    let target = ctx.shared.target.lock().unwrap().clone();
+    let generation = ctx.shared.library_gen.fetch_add(1, Ordering::SeqCst) + 1;
+    set_library.call(LibraryState::default()); // Loading, no art
+    let (shared, identity, set) = (
+        ctx.shared.clone(),
+        ctx.identity.clone(),
+        set_library.clone(),
+    );
+    std::thread::Builder::new()
+        .name("pf-library".into())
+        .spawn(move || {
+            let pin = target.fp_hex.as_deref().and_then(crate::trust::parse_hex32);
+            let publish = |state: &LibraryState| {
+                if shared.library_gen.load(Ordering::SeqCst) == generation {
+                    set.call(state.clone());
+                }
+            };
+            let mut state = LibraryState::default();
+            let games = match library::fetch_games(
+                &target.addr,
+                library::DEFAULT_MGMT_PORT,
+                &identity,
+                pin,
+            ) {
+                Ok(games) => games,
+                Err(e) => {
+                    state.phase = LibraryPhase::Failed(e.to_string());
+                    return publish(&state);
+                }
+            };
+            if games.is_empty() {
+                state.phase = LibraryPhase::Empty;
+                return publish(&state);
+            }
+
+            // Seed cached posters; queue the art pipeline for the rest.
+            let base = library::base_url(&target.addr, library::DEFAULT_MGMT_PORT);
+            let cache = art_cache_dir();
+            let mut jobs: VecDeque<(String, Vec<String>)> = VecDeque::new();
+            for g in &games {
+                match cache.as_deref().and_then(|d| cached_art_uri(d, &g.id)) {
+                    Some(uri) => {
+                        state.art.insert(g.id.clone(), uri);
+                    }
+                    None => {
+                        let candidates = g.art.poster_candidates(&base);
+                        if !candidates.is_empty() {
+                            jobs.push_back((g.id.clone(), candidates));
+                        }
+                    }
+                }
+            }
+            state.phase = LibraryPhase::Ready(
+                games
+                    .iter()
+                    .map(|g| Game {
+                        id: g.id.clone(),
+                        title: g.title.clone(),
+                        store: g.store.clone(),
+                    })
+                    .collect(),
+            );
+            publish(&state);
+
+            if jobs.is_empty() {
+                return;
+            }
+            let rx = library::spawn_art_fetch(base, identity, pin, jobs);
+            while let Ok((id, bytes)) = rx.recv_blocking() {
+                if shared.library_gen.load(Ordering::SeqCst) != generation {
+                    return; // superseded — stop touching state (and the cache is shared anyway)
+                }
+                if let Some(uri) = cache.as_deref().and_then(|d| store_art(d, &id, &bytes)) {
+                    state.art.insert(id, uri);
+                    publish(&state);
+                }
+            }
+        })
+        .ok();
+}
+
+/// `%LOCALAPPDATA%\punktfunk\art-cache` — poster bytes by game id, so the `Image` widget
+/// has a `file:///` URI to load and revisits skip the network entirely. Small (one poster
+/// per library entry); no eviction yet.
+fn art_cache_dir() -> Option<PathBuf> {
+    let base = std::env::var_os("LOCALAPPDATA")?;
+    Some(PathBuf::from(base).join("punktfunk").join("art-cache"))
+}
+
+/// The cache filename for a game id (`steam:570` → `steam_570.img`) — ids are short and
+/// store-qualified, so the sanitized form stays unique in practice.
+fn art_file(dir: &Path, id: &str) -> PathBuf {
+    let safe: String = id
+        .chars()
+        .map(|c| if c.is_ascii_alphanumeric() { c } else { '_' })
+        .collect();
+    dir.join(format!("{safe}.img"))
+}
+
+fn cached_art_uri(dir: &Path, id: &str) -> Option<String> {
+    let p = art_file(dir, id);
+    p.exists().then(|| file_uri(&p))
+}
+
+fn store_art(dir: &Path, id: &str, bytes: &[u8]) -> Option<String> {
+    std::fs::create_dir_all(dir).ok()?;
+    let p = art_file(dir, id);
+    std::fs::write(&p, bytes).ok()?;
+    Some(file_uri(&p))
+}
+
+fn file_uri(p: &Path) -> String {
+    format!("file:///{}", p.display().to_string().replace('\\', "/"))
+}
+
+/// The store badge text — shared spelling with the GTK page and the console UI's posters.
+fn store_label(store: &str) -> &'static str {
+    match store {
+        "steam" => "Steam",
+        "custom" => "Custom",
+        "heroic" => "Heroic",
+        "lutris" => "Lutris",
+        "epic" => "Epic",
+        "gog" => "GOG",
+        "xbox" => "Xbox",
+        _ => "Game",
+    }
+}
+
+/// Monogram for the placeholder poster: the first letters of the first two words.
+fn initials(title: &str) -> String {
+    title
+        .split_whitespace()
+        .take(2)
+        .filter_map(|w| w.chars().next())
+        .flat_map(char::to_uppercase)
+        .collect()
+}
+
+/// One poster tile: the artwork (or a monogram placeholder while it loads) with the store
+/// badge overlaid top-left, the title below, tap-to-launch across the whole tile.
+fn poster_tile(
+    game: &Game,
+    art_uri: Option<&str>,
+    poster_h: f64,
+    on_tap: Box<dyn Fn()>,
+) -> Element {
+    let poster: Element = match art_uri {
+        Some(uri) => Image::new_with_uri(uri)
+            .stretch(Stretch::UniformToFill)
+            .height(poster_h)
+            .into(),
+        None => border(
+            text_block(initials(&game.title))
+                .font_size(28.0)
+                .semibold()
+                .foreground(ThemeRef::SecondaryText)
+                .horizontal_alignment(HorizontalAlignment::Center)
+                .vertical_alignment(VerticalAlignment::Center),
+        )
+        .background(ThemeRef::SubtleFill)
+        .height(poster_h)
+        .into(),
+    };
+    let framed = border(grid(vec![
+        poster,
+        pill(store_label(&game.store), Pill::Neutral)
+            .horizontal_alignment(HorizontalAlignment::Left)
+            .vertical_alignment(VerticalAlignment::Top)
+            .margin(uniform(6.0))
+            .into(),
+    ]))
+    .corner_radius(8.0)
+    .border_brush(ThemeRef::CardStroke)
+    .border_thickness(uniform(1.0));
+
+    border(
+        vstack((
+            framed,
+            text_block(&game.title)
+                .font_size(12.0)
+                .wrap()
+                .margin(edges(2.0, 6.0, 2.0, 0.0)),
+        ))
+        .spacing(0.0),
+    )
+    .background(hit_test_backstop())
+    .on_tapped(on_tap)
+    .into()
+}
+
+pub(crate) fn library_page(props: &LibraryProps, cx: &mut RenderCx) -> Element {
+    let ctx = &props.svc.ctx;
+    let target = ctx.shared.target.lock().unwrap().clone();
+    let (ss, st) = (props.svc.set_screen.clone(), props.svc.set_status.clone());
+
+    // Responsive poster columns from the live window width (the hosts page's pattern).
+    let window = cx.use_inner_size();
+    let content_w = (window.width - 64.0).clamp(POSTER_MIN_WIDTH, 1120.0);
+    let cols =
+        (((content_w + POSTER_GAP) / (POSTER_MIN_WIDTH + POSTER_GAP)).floor() as usize).clamp(2, 6);
+    let tile_w = (content_w - POSTER_GAP * (cols as f64 - 1.0)) / cols as f64;
+    let poster_h = tile_w * POSTER_RATIO;
+
+    let back_btn = button("Back").icon(Symbol::Back).on_click({
+        let ss = ss.clone();
+        move || ss.call(Screen::Hosts)
+    });
+    let title = if target.name.is_empty() {
+        "Game library".to_string()
+    } else {
+        format!("Game library \u{00B7} {}", target.name)
+    };
+    let mut body: Vec<Element> = vec![page_header(&title, back_btn)];
+
+    match &props.state.phase {
+        LibraryPhase::Loading => body.push(
+            card(
+                hstack((
+                    ProgressRing::indeterminate().width(18.0).height(18.0),
+                    text_block("Loading the library\u{2026}").foreground(ThemeRef::SecondaryText),
+                ))
+                .spacing(12.0),
+            )
+            .into(),
+        ),
+        LibraryPhase::Failed(msg) => {
+            body.push(
+                InfoBar::new("Couldn't load the library")
+                    .message(msg.clone())
+                    .error()
+                    .is_closable(false)
+                    .into(),
+            );
+            let (ctx2, set_library) = (ctx.clone(), props.svc.set_library.clone());
+            body.push(
+                button("Retry")
+                    .accent()
+                    .icon(Symbol::Refresh)
+                    .on_click(move || start_fetch(&ctx2, &set_library))
+                    .horizontal_alignment(HorizontalAlignment::Left)
+                    .into(),
+            );
+        }
+        LibraryPhase::Empty => body.push(
+            card(
+                text_block(
+                    "No games yet \u{2014} add titles to the host's library (its console or web \
+                     UI) and they appear here.",
+                )
+                .wrap()
+                .foreground(ThemeRef::SecondaryText),
+            )
+            .into(),
+        ),
+        LibraryPhase::Ready(games) => {
+            let tiles: Vec<Element> = games
+                .iter()
+                .map(|g| {
+                    let (ctx2, ss, st) = (ctx.clone(), ss.clone(), st.clone());
+                    let (target, id) = (target.clone(), g.id.clone());
+                    poster_tile(
+                        g,
+                        props.state.art.get(&g.id).map(String::as_str),
+                        poster_h,
+                        Box::new(move || {
+                            initiate_launch(&ctx2, target.clone(), id.clone(), &ss, &st)
+                        }),
+                    )
+                })
+                .collect();
+            body.push(tile_grid(tiles, cols, POSTER_GAP));
+        }
+    }
+
+    page_wide(body)
+}

clients/windows/src/app/mod.rs

@@ -26,6 +26,7 @@
 mod connect;
 mod help;
 mod hosts;
+mod library;
 mod licenses;
 mod pair;
 mod settings;
@@ -67,6 +68,9 @@ pub(crate) enum Screen {
     Pair,
     /// Per-host network speed test (probe burst + recommended bitrate).
     SpeedTest,
+    /// The target host's game library (poster grid; tap-to-launch) — paired hosts only,
+    /// behind the "Show game library" experimental toggle.
+    Library,
 }
 
 /// The host we're about to connect to / pair with / speed-test (carried into those screens
@@ -100,6 +104,9 @@ pub(crate) struct Svc {
     /// Speed-test lifecycle lives in root state (thread-driven — see the module docs); the hosts
     /// page resets it to `Running` before navigating, the probe worker completes it.
     pub(crate) set_speed: AsyncSetState<SpeedState>,
+    /// Library fetch/art state — root for the same reason; the hosts page kicks a fetch
+    /// off before navigating, the worker (and the art stream) completes it.
+    pub(crate) set_library: AsyncSetState<library::LibraryState>,
 }
 
 impl PartialEq for Svc {
@@ -138,6 +145,9 @@ pub(crate) struct Shared {
     /// Whether the live session child is a `--browse` console-UI run (vs a stream) — the
     /// session status page words itself accordingly. Set by each spawn.
     pub(crate) browse: std::sync::atomic::AtomicBool,
+    /// Library-fetch generation (the speed test's guard pattern): bumped per fetch so a
+    /// superseded worker (re-open, Retry, another host) stops publishing.
+    pub(crate) library_gen: std::sync::atomic::AtomicU64,
 }
 
 pub struct AppCtx {
@@ -270,6 +280,8 @@ fn root(cx: &mut RenderCx, ctx: &Arc<AppCtx>) -> Element {
     // Saved-host reachability, keyed by `fp_hex`, refreshed by the probe sweep below. Root state
     // (thread-driven → must be root to re-render — see the module docs), passed to the hosts page.
     let (probed, set_probed) = cx.use_async_state(HashMap::<String, bool>::new());
+    // Library fetch/art state (thread-driven → root; see `library::start_fetch`).
+    let (library, set_library) = cx.use_async_state(library::LibraryState::default());
 
     // Continuous LAN discovery (spawned once).
     cx.use_effect((), {
@@ -468,6 +480,7 @@ fn root(cx: &mut RenderCx, ctx: &Arc<AppCtx>) -> Element {
         set_screen: set_screen.clone(),
         set_status: set_status.clone(),
         set_speed: set_speed.clone(),
+        set_library: set_library.clone(),
     };
     let body = match &screen {
         Screen::Hosts => component(
@@ -505,6 +518,13 @@ fn root(cx: &mut RenderCx, ctx: &Arc<AppCtx>) -> Element {
         Screen::Help => help::help_page(&set_screen),
         Screen::Pair => component(pair::pair_page, svc),
         Screen::SpeedTest => component(speed::speed_page, SpeedProps { svc, state: speed }),
+        Screen::Library => component(
+            library::library_page,
+            library::LibraryProps {
+                svc,
+                state: library,
+            },
+        ),
         // Spawn mode (the default): the stream runs in the punktfunk-session child's own
         // window; this screen is a status page (no hooks — inline is sound). The legacy
         // in-process SwapChainPanel page stays behind the "Streaming engine" setting /

clients/windows/src/app/settings.rs

@@ -343,6 +343,16 @@ pub(crate) fn settings_page(
         let ss = set_screen.clone();
         button("Third-party licenses").on_click(move || ss.call(Screen::Licenses))
     };
+    let library_toggle = setting_toggle(
+        ctx,
+        "Show game library (experimental)",
+        s.library_enabled,
+        |s, on| s.library_enabled = on,
+    )
+    .tooltip(
+        "Adds \u{201C}Browse library\u{2026}\u{201D} to paired hosts \u{2014} pick a game and it \
+         launches in the stream. Mirrors the Apple client's toggle.",
+    );
 
     // The selected section's content — per-control guidance lives on hover tooltips, so the
     // card is just the controls.
@@ -375,7 +385,10 @@ pub(crate) fn settings_page(
             "Audio",
             settings_card(vec![channels_combo.into(), mic_toggle.into()]),
         ),
-        "about" => ("About", settings_card(vec![licenses_button.into()])),
+        "about" => (
+            "About",
+            settings_card(vec![library_toggle.into(), licenses_button.into()]),
+        ),
         _ => (
             "Display",
             settings_card(vec![

clients/windows/src/app/style.rs

@@ -88,6 +88,23 @@ pub(crate) fn page_wide(children: Vec<Element>) -> Element {
     scroll_view(col).into()
 }
 
+/// Lay tiles into a `cols`-wide grid of equal-width star columns (rows share the height of
+/// their tallest tile, so a grid row always lines up). Shared by the hosts page's host
+/// tiles and the library page's posters.
+pub(crate) fn tile_grid(tiles: Vec<Element>, cols: usize, gap: f64) -> Element {
+    let rows = tiles.len().div_ceil(cols);
+    let mut children = Vec::with_capacity(tiles.len());
+    for (i, t) in tiles.into_iter().enumerate() {
+        children.push(t.grid_row((i / cols) as i32).grid_column((i % cols) as i32));
+    }
+    grid(children)
+        .columns(vec![GridLength::Star(1.0); cols])
+        .rows(vec![GridLength::Auto; rows])
+        .column_spacing(gap)
+        .row_spacing(gap)
+        .into()
+}
+
 /// A page header: a large bold title on the left, one action button on the right.
 pub(crate) fn page_header(title: &str, action: Button) -> Element {
     grid((

clients/windows/src/shell_window.rs

@@ -10,9 +10,9 @@
 //! `stream::window_dpi`.
 
 use std::sync::atomic::{AtomicIsize, Ordering};
-use windows::Win32::Foundation::HWND;
+use windows::Win32::Foundation::{HWND, RECT};
 use windows::Win32::UI::WindowsAndMessaging::{
-    FindWindowW, IsWindow, SetForegroundWindow, ShowWindow, SW_HIDE, SW_SHOW,
+    FindWindowW, GetWindowRect, IsWindow, SetForegroundWindow, ShowWindow, SW_HIDE, SW_SHOW,
 };
 
 static SHELL_HWND: AtomicIsize = AtomicIsize::new(0);
@@ -53,3 +53,13 @@ pub(crate) fn restore() {
         }
     }
 }
+
+/// The shell window's top-left in desktop coordinates — passed to the spawned session
+/// (`--window-pos`) so its window opens on the SAME monitor, roughly where the shell is,
+/// and the visibility handoff reads as one window changing content.
+pub(crate) fn position() -> Option<(i32, i32)> {
+    let h = shell_hwnd()?;
+    let mut r = RECT::default();
+    unsafe { GetWindowRect(h, &mut r).ok()? };
+    Some((r.left, r.top))
+}

clients/windows/src/spawn.rs

@@ -97,6 +97,7 @@ pub(crate) fn session_binary() -> std::path::PathBuf {
 /// streams fullscreen" toggle); `launch` carries a library title id for the host to
 /// launch during the handshake. `Err` = the spawn itself failed (binary missing?) —
 /// surfaced as a connect error by the caller.
+#[allow(clippy::too_many_arguments)] // one cohesive spawn spec (session_params precedent)
 pub(crate) fn spawn_session(
     addr: &str,
     port: u16,
@@ -120,6 +121,7 @@ pub(crate) fn spawn_session(
     if let Some(id) = launch {
         cmd.arg("--launch").arg(id);
     }
+    add_window_pos(&mut cmd);
     spawn_with(cmd, &format!("{addr}:{port}"), slot, on_event)
 }
 
@@ -141,9 +143,19 @@ pub(crate) fn spawn_browse(
     if fullscreen {
         cmd.arg("--fullscreen");
     }
+    add_window_pos(&mut cmd);
     spawn_with(cmd, &format!("{addr}:{port}"), slot, on_event)
 }
 
+/// Hand the shell window's position to the child (`--window-pos`) so the session window
+/// opens on the same monitor, where the shell is — the hide/restore handoff then reads as
+/// one window changing content instead of a window jumping displays.
+fn add_window_pos(cmd: &mut Command) {
+    if let Some((x, y)) = crate::shell_window::position() {
+        cmd.arg("--window-pos").arg(format!("{x},{y}"));
+    }
+}
+
 /// The shared spawn + stdout-contract reader behind [`spawn_session`]/[`spawn_browse`].
 fn spawn_with(
     mut cmd: Command,

crates/pf-client-core/src/trust.rs

@@ -246,11 +246,12 @@ pub fn probe_reachable_many(
 ) -> Vec<bool> {
     let handles: Vec<_> = targets
         .into_iter()
-        .map(|(addr, port)| {
+        .map(|(addr, port)| std::thread::spawn(move || NativeClient::probe(&addr, port, timeout)))
-            std::thread::spawn(move || NativeClient::probe(&addr, port, timeout))
-        })
         .collect();
-    handles.into_iter().map(|h| h.join().unwrap_or(false)).collect()
+    handles
+        .into_iter()
+        .map(|h| h.join().unwrap_or(false))
+        .collect()
 }
 
 /// App settings, persisted as JSON. Stringly-typed gamepad/compositor prefs so the file

crates/pf-presenter/src/run.rs

@@ -31,6 +31,12 @@ pub struct SessionOpts {
     pub window_title: String,
     /// Start fullscreen (gamescope / `--fullscreen`).
     pub fullscreen: bool,
+    /// The window's top-left in desktop coordinates; `None` = centered on the primary
+    /// display. The shells pass their own window's position so the stream opens on the
+    /// SAME monitor (and the shell⇄session visibility handoff reads as one window
+    /// changing content, not a window jumping displays). Fullscreen follows the display
+    /// this lands on.
+    pub window_pos: Option<(i32, i32)>,
     /// Print `stats:` lines (Ctrl+Alt+Shift+S toggles live).
     pub print_stats: bool,
     /// Emit the `{"ready":true}` stdout line after the first presented frame.
@@ -239,7 +245,11 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
         .map_err(|e| anyhow::anyhow!("register FrameWake event: {e}"))?;
     let mut window = {
         let mut b = video.window(&opts.window_title, 1280, 720);
-        b.position_centered().resizable().vulkan();
+        match opts.window_pos {
+            Some((x, y)) => b.position(x, y),
+            None => b.position_centered(),
+        };
+        b.resizable().vulkan();
         if opts.fullscreen {
             b.fullscreen();
         }