feat(app): Wayland support + monitor-relative default window size

Two related platform-fit fixes for desktop launch:

1. Wayland session compatibility. The workspace Cargo.toml's
   Bevy feature list previously enabled only `x11`, leaving
   winit-on-Wayland to fall through to XWayland — the game
   rendered inside an X11 frame stitched into the Wayland
   compositor instead of as a native Wayland client. Adding
   the `wayland` feature lets winit prefer Wayland when
   WAYLAND_DISPLAY is set on the session, falling back to X11
   when it isn't. Costs a few hundred KB of binary for the
   libwayland-client bindings; comment in Cargo.toml explains
   the trade.

2. Smart default window sizing. The fallback window size for
   first launches (no saved geometry) was a fixed 1280x800. On
   a 4K monitor that's a comparatively tiny window in one
   corner; the game's cards then occupy a small physical area
   even though the screen has plenty of room. New
   `apply_smart_default_window_size` Update system queries
   `Monitor` (with the `PrimaryMonitor` marker) and resizes the
   primary window to ~70% of the monitor's *logical* size on
   the first frame. Logical size already factors in the OS's
   HiDPI scale factor, so:

   - 1920x1080 / 1.0 scale → 1344x756 target
   - 2560x1440 / 1.0 scale → 1792x1008 target
   - 3840x2160 / 1.0 scale → 2688x1512 target
   - 2880x1800 / 2.0 scale (Retina) → 1008x630 target
                  (same physical size as 1080p)

   Clamped to the existing 800x600 minimum so old systems
   don't get sub-minimum windows. Skipped entirely when saved
   geometry was applied — the player's chosen size always
   wins. Uses `Local<bool>` for one-shot semantics; the early-
   exit per tick costs nothing once `*applied` is true.

Workspace: 1170 passing tests / 0 failing. cargo clippy
--workspace --all-targets -- -D warnings clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Cargo.lock

@@ -126,6 +126,19 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.8.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a15f179cd60c4584b8a8c596927aadc462e27f2ca70c04e0071964a73ba7a75"
+dependencies = [
+ "cfg-if",
+ "getrandom 0.3.4",
+ "once_cell",
+ "version_check",
+ "zerocopy",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.4"
@@ -719,7 +732,7 @@ dependencies = [
  "cfg-if",
  "console_error_panic_hook",
  "ctrlc",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "log",
  "thiserror 2.0.18",
  "variadics_please",
@@ -753,7 +766,7 @@ dependencies = [
  "crossbeam-channel",
  "derive_more",
  "disqualified",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "either",
  "futures-io",
  "futures-lite",
@@ -801,7 +814,7 @@ dependencies = [
  "bevy_utils",
  "bevy_window",
  "derive_more",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "serde",
  "smallvec",
  "thiserror 2.0.18",
@@ -1200,7 +1213,7 @@ dependencies = [
  "bevy_utils",
  "derive_more",
  "disqualified",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "erased-serde",
  "foldhash 0.2.0",
  "glam 0.30.10",
@@ -1259,7 +1272,7 @@ dependencies = [
  "bitflags 2.11.1",
  "bytemuck",
  "derive_more",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "encase",
  "fixedbitset",
  "glam 0.30.10",
@@ -1854,6 +1867,18 @@ dependencies = [
  "thiserror 1.0.69",
 ]
 
+[[package]]
+name = "calloop-wayland-source"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95a66a987056935f7efce4ab5668920b5d0dac4a7c99991a67395f13702ddd20"
+dependencies = [
+ "calloop",
+ "rustix 0.38.44",
+ "wayland-backend",
+ "wayland-client",
+]
+
 [[package]]
 name = "cbc"
 version = "0.1.2"
@@ -2709,6 +2734,12 @@ version = "0.15.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1aaf95b3e5c8f23aa320147307562d361db0ae0d51242340f558153b4eb2439b"
 
+[[package]]
+name = "downcast-rs"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75b325c5dbd37f80359721ad39aca5a29fb04c89279657cffdda8736d0c0b9d2"
+
 [[package]]
 name = "downcast-rs"
 version = "2.0.2"
@@ -5792,6 +5823,15 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a993555f31e5a609f617c12db6250dedcac1b0a85076912c436e6fc9b2c8e6a3"
 
+[[package]]
+name = "quick-xml"
+version = "0.39.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "958f21e8e7ceb5a1aa7fa87fab28e7c75976e0bfe7e23ff069e0a260f894067d"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "quinn"
 version = "0.11.9"
@@ -6165,7 +6205,7 @@ dependencies = [
  "pico-args",
  "rgb",
  "svgtypes",
- "tiny-skia",
+ "tiny-skia 0.12.0",
  "usvg",
  "zune-jpeg",
 ]
@@ -6502,6 +6542,19 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "sctk-adwaita"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6277f0217056f77f1d8f49f2950ac6c278c0d607c45f5ee99328d792ede24ec"
+dependencies = [
+ "ab_glyph",
+ "log",
+ "memmap2",
+ "smithay-client-toolkit",
+ "tiny-skia 0.11.4",
+]
+
 [[package]]
 name = "sec1"
 version = "0.7.3"
@@ -6846,6 +6899,31 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "smithay-client-toolkit"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3457dea1f0eb631b4034d61d4d8c32074caa6cd1ab2d59f2327bd8461e2c0016"
+dependencies = [
+ "bitflags 2.11.1",
+ "calloop",
+ "calloop-wayland-source",
+ "cursor-icon",
+ "libc",
+ "log",
+ "memmap2",
+ "rustix 0.38.44",
+ "thiserror 1.0.69",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-csd-frame",
+ "wayland-cursor",
+ "wayland-protocols",
+ "wayland-protocols-wlr",
+ "wayland-scanner",
+ "xkeysym",
+]
+
 [[package]]
 name = "smol_str"
 version = "0.2.2"
@@ -6938,7 +7016,7 @@ dependencies = [
  "solitaire_sync",
  "tempfile",
  "thiserror 2.0.18",
- "tiny-skia",
+ "tiny-skia 0.12.0",
  "tokio",
  "usvg",
  "uuid",
@@ -7525,7 +7603,7 @@ dependencies = [
  "crc32fast",
  "crossbeam-channel",
  "datasketches",
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "fastdivide",
  "fnv",
  "fs4",
@@ -7577,7 +7655,7 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c57166f5bcfd478f370ab8445afb4678dce44801fa5ce5c451aaf8595583c5dc"
 dependencies = [
- "downcast-rs",
+ "downcast-rs 2.0.2",
  "fastdivide",
  "itertools 0.14.0",
  "serde",
@@ -7765,6 +7843,20 @@ dependencies = [
  "time-core",
 ]
 
+[[package]]
+name = "tiny-skia"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83d13394d44dae3207b52a326c0c85a8bf87f1541f23b0d143811088497b09ab"
+dependencies = [
+ "arrayref",
+ "arrayvec",
+ "bytemuck",
+ "cfg-if",
+ "log",
+ "tiny-skia-path 0.11.4",
+]
+
 [[package]]
 name = "tiny-skia"
 version = "0.12.0"
@@ -7777,7 +7869,18 @@ dependencies = [
  "cfg-if",
  "log",
  "png 0.18.1",
- "tiny-skia-path",
+ "tiny-skia-path 0.12.0",
+]
+
+[[package]]
+name = "tiny-skia-path"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c9e7fc0c2e86a30b117d0462aa261b72b7a99b7ebd7deb3a14ceda95c5bdc93"
+dependencies = [
+ "arrayref",
+ "bytemuck",
+ "strict-num",
 ]
 
 [[package]]
@@ -8548,7 +8651,7 @@ dependencies = [
  "siphasher",
  "strict-num",
  "svgtypes",
- "tiny-skia-path",
+ "tiny-skia-path 0.12.0",
  "ttf-parser",
  "unicode-bidi",
  "unicode-script",
@@ -8754,6 +8857,114 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "wayland-backend"
+version = "0.3.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2857dd20b54e916ec7253b3d6b4d5c4d7d4ca2c33c2e11c6c76a99bd8744755d"
+dependencies = [
+ "cc",
+ "downcast-rs 1.2.1",
+ "rustix 1.1.4",
+ "scoped-tls",
+ "smallvec",
+ "wayland-sys",
+]
+
+[[package]]
+name = "wayland-client"
+version = "0.31.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "645c7c96bb74690c3189b5c9cb4ca1627062bb23693a4fad9d8c3de958260144"
+dependencies = [
+ "bitflags 2.11.1",
+ "rustix 1.1.4",
+ "wayland-backend",
+ "wayland-scanner",
+]
+
+[[package]]
+name = "wayland-csd-frame"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "625c5029dbd43d25e6aa9615e88b829a5cad13b2819c4ae129fdbb7c31ab4c7e"
+dependencies = [
+ "bitflags 2.11.1",
+ "cursor-icon",
+ "wayland-backend",
+]
+
+[[package]]
+name = "wayland-cursor"
+version = "0.31.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a52d18780be9b1314328a3de5f930b73d2200112e3849ca6cb11822793fb34d"
+dependencies = [
+ "rustix 1.1.4",
+ "wayland-client",
+ "xcursor",
+]
+
+[[package]]
+name = "wayland-protocols"
+version = "0.32.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "563a85523cade2429938e790815fd7319062103b9f4a2dc806e9b53b95982d8f"
+dependencies = [
+ "bitflags 2.11.1",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-scanner",
+]
+
+[[package]]
+name = "wayland-protocols-plasma"
+version = "0.3.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b6d8cf1eb2c1c31ed1f5643c88a6e53538129d4af80030c8cabd1f9fa884d91"
+dependencies = [
+ "bitflags 2.11.1",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-protocols",
+ "wayland-scanner",
+]
+
+[[package]]
+name = "wayland-protocols-wlr"
+version = "0.3.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb04e52f7836d7c7976c78ca0250d61e33873c34156a2a1fc9474828ec268234"
+dependencies = [
+ "bitflags 2.11.1",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-protocols",
+ "wayland-scanner",
+]
+
+[[package]]
+name = "wayland-scanner"
+version = "0.31.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c324a910fd86ebdc364a3e61ec1f11737d3b1d6c273c0239ee8ff4bc0d24b4a"
+dependencies = [
+ "proc-macro2",
+ "quick-xml",
+ "quote",
+]
+
+[[package]]
+name = "wayland-sys"
+version = "0.31.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8eab23fefc9e41f8e841df4a9c707e8a8c4ed26e944ef69297184de2785e3be"
+dependencies = [
+ "dlib",
+ "log",
+ "pkg-config",
+]
+
 [[package]]
 name = "web-sys"
 version = "0.3.97"
@@ -9569,6 +9780,7 @@ version = "0.30.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a6755fa58a9f8350bd1e472d4c3fcc25f824ec358933bba33306d0b63df5978d"
 dependencies = [
+ "ahash",
  "android-activity",
  "atomic-waker",
  "bitflags 2.11.1",
@@ -9583,6 +9795,7 @@ dependencies = [
  "dpi",
  "js-sys",
  "libc",
+ "memmap2",
  "ndk",
  "objc2 0.5.2",
  "objc2-app-kit 0.2.2",
@@ -9594,11 +9807,17 @@ dependencies = [
  "raw-window-handle",
  "redox_syscall 0.4.1",
  "rustix 0.38.44",
+ "sctk-adwaita",
+ "smithay-client-toolkit",
  "smol_str",
  "tracing",
  "unicode-segmentation",
  "wasm-bindgen",
  "wasm-bindgen-futures",
+ "wayland-backend",
+ "wayland-client",
+ "wayland-protocols",
+ "wayland-protocols-plasma",
  "web-sys",
  "web-time",
  "windows-sys 0.52.0",
@@ -9766,6 +9985,12 @@ version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea6fc2961e4ef194dcbfe56bb845534d0dc8098940c7e5c012a258bfec6701bd"
 
+[[package]]
+name = "xcursor"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bec9e4a500ca8864c5b47b8b482a73d62e4237670e5b5f1d6b9e3cae50f28f2b"
+
 [[package]]
 name = "xkbcommon-dl"
 version = "0.4.2"

Cargo.toml

@@ -54,11 +54,16 @@ bevy = { version = "0.18", default-features = false, features = [
     "bevy_window",
     "custom_cursor",
     "reflect_auto_register",
-    # default_platform (desktop subset; no android/wayland/webgl/gilrs/sysinfo)
+    # default_platform (desktop subset; no android/webgl/gilrs/sysinfo)
     "std",
     "bevy_winit",
     "default_font",
     "multi_threaded",
+    # winit prefers Wayland when WAYLAND_DISPLAY is set on the
+    # session and falls through to X11 otherwise. Without `wayland`,
+    # winit-on-Wayland-session falls back to XWayland which renders
+    # the game in an X11 frame inside the Wayland compositor.
+    "wayland",
     "x11",
     # common_api
     "bevy_color",

solitaire_app/src/main.rs

@@ -3,7 +3,9 @@ use std::io::Write;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use bevy::prelude::*;
-use bevy::window::{MonitorSelection, PresentMode, WindowPosition};
+use bevy::window::{
+    Monitor, MonitorSelection, PresentMode, PrimaryMonitor, PrimaryWindow, WindowPosition,
+};
 use solitaire_data::{load_settings_from, provider_for_backend, settings_file_path, Settings};
 use solitaire_engine::{
     register_theme_asset_sources, AchievementPlugin, AnimationPlugin, AssetSourcesPlugin,
@@ -43,8 +45,10 @@ fn main() {
 
     // Restore the previous window geometry if the player has one saved.
     // Otherwise open at the platform default (1280×800, centred on the
-    // primary monitor). The window_geometry field is None on first run
+    // primary monitor) — `apply_smart_default_window_size` will resize
-    // and after upgrading from a build that didn't persist geometry.
+    // up to a monitor-relative target on the first frame so HiDPI / 4K
+    // sessions don't end up with a comparatively tiny window.
+    let had_saved_geometry = settings.window_geometry.is_some();
     let (window_resolution, window_position) = match settings.window_geometry {
         Some(geom) => (
             (geom.width, geom.height).into(),
@@ -141,8 +145,78 @@ fn main() {
         .add_plugins(UiModalPlugin)
         .add_plugins(UiFocusPlugin)
         .add_plugins(UiTooltipPlugin)
-        .add_plugins(SplashPlugin)
+        .add_plugins(SplashPlugin);
-        .run();
+
+    // Smart default window sizing: when no saved geometry was loaded,
+    // resize the freshly-opened 1280×800 window to ~70 % of the primary
+    // monitor's logical size on the first frame. Without this, a 4K
+    // monitor opens the same 1280×800 window that a 1080p monitor
+    // does — visually tiny relative to screen. Skipped entirely when
+    // saved geometry was applied; the player's preference always wins.
+    if !had_saved_geometry {
+        app.add_systems(Update, apply_smart_default_window_size);
+    }
+
+    app.run();
+}
+
+/// One-shot Update system that runs only on launches without saved
+/// window geometry. Resizes the primary window to a fraction of the
+/// primary monitor's *logical* size — bigger monitors get bigger
+/// windows automatically. Logical size already accounts for the OS's
+/// HiDPI scale factor, so a 2880×1800 Retina display reporting
+/// scale_factor 2.0 yields a 1440×900 logical size and a 1008×630
+/// target window — same physical inches as a 1920×1080 monitor with
+/// scale_factor 1.0 yielding 1344×756.
+///
+/// Uses `Local<bool>` to make itself one-shot rather than introducing
+/// a dedicated resource. The Update tick is necessary because Bevy
+/// populates the `Monitor` entities asynchronously after winit's
+/// Resumed event fires; they may not exist on the first Startup pass.
+fn apply_smart_default_window_size(
+    mut applied: Local<bool>,
+    monitors: Query<&Monitor, With<PrimaryMonitor>>,
+    mut windows: Query<&mut Window, With<PrimaryWindow>>,
+) {
+    if *applied {
+        return;
+    }
+    let Ok(monitor) = monitors.single() else {
+        // Primary monitor not yet spawned by bevy_winit. Try again
+        // next frame; the cost is one early-exit per tick until
+        // monitors arrive (typically frame 1 or 2).
+        return;
+    };
+    let Ok(mut window) = windows.single_mut() else {
+        return;
+    };
+
+    let scale = monitor.scale_factor as f32;
+    if scale <= 0.0 {
+        // Defensive: a zero or negative scale factor would NaN the
+        // arithmetic below. Bail and accept the default size.
+        *applied = true;
+        return;
+    }
+    let logical_w = monitor.physical_width as f32 / scale;
+    let logical_h = monitor.physical_height as f32 / scale;
+
+    // Target 70 % of monitor in each dimension, clamped to the
+    // existing 800×600 minimum and the monitor's own logical size
+    // (so we never request a window larger than the screen).
+    let target_w = (logical_w * 0.7).clamp(800.0, logical_w);
+    let target_h = (logical_h * 0.7).clamp(600.0, logical_h);
+
+    // Resize only when the change is meaningful — at exactly 1280×800
+    // on a 1920×1080 monitor the new target is 1344×756 (only ~5 %
+    // wider), worth the resize; at the same default on an 800×600
+    // monitor the clamp pins us at 800×600 and we shouldn't resize.
+    let curr_w = window.resolution.width();
+    let curr_h = window.resolution.height();
+    if (curr_w - target_w).abs() > 8.0 || (curr_h - target_h).abs() > 8.0 {
+        window.resolution.set(target_w, target_h);
+    }
+    *applied = true;
 }
 
 /// Wraps the default panic hook with one that also appends a crash log