Linux: session-native GDK/WebKit mitigations and in-page browse scroll (#731)

* feat(linux): session GDK defaults, nvidia-quirk, optional x11-legacy wrap

Ship PSYSONIC_ALLOW_NATIVE_GDK from Nix/AUR instead of pinning WEBKIT_DISABLE_*
and GDK x11. Add flake psysonic-x11-legacy for the old wrap; alias gdk-session
to psysonic. Startup uses webkit2gtk-nvidia-quirk and Wayland-aware compositing;
refresh Help (a45) and nixos-install docs.

* fix(linux): session GDK and nvidia-quirk only; drop wrapper env heuristics

Remove PSYSONIC_ALLOW_NATIVE_GDK and devShell GDK/WEBKIT exports; stop
synthesizing GDK/WebKit vars in main.rs. Update Nix/AUR wrappers, install
docs, CHANGELOG, and help FAQ with practical user-facing workarounds.

* fix(linux): X11-pinned GDK uses DMABUF quirk path, not Wayland explicit-sync

When GDK_BACKEND is forced to x11 on a wayland user session, webkit2gtk-nvidia-quirk
would still apply __NV_DISABLE_EXPLICIT_SYNC and gray out the webview. Map that case
to WEBKIT_DISABLE_DMABUF_RENDERER like native X11.

* fix(ui): stabilize WebKitGTK/Wayland hover paint for nav and media cards

Sidebar nav links avoid transition:all and promote icons with translateZ(0).
Artist rows and album/artist/song cards use compositing hints; card shadows
and borders no longer interpolate so cover zoom can stay smooth without jitter.

* fix(ui): isolate artist/album card text and cover paint on WebKitGTK

Promote cover blocks with contain/paint and text stacks with translateZ(0);
use artist-card-info on the artists grid for the same layout as other cards.

* feat(artists): in-page overlay scroll and locked main viewport

Move list/grid into an inner OverlayScrollArea, stop sticky toolbar from
owning the route scroll, align the rail with the main panel edge, and skip
the main-route overlay thumb when the viewport cannot scroll vertically.

* feat(browse): extend in-page overlay scroll to more library routes

Reuse the locked main viewport pattern from Artists for Albums, Composers,
Lossless albums, and New releases; wire VirtualCardGrid and scroll chrome
to the matching in-page viewport ids.

* fix(linux): improve Wayland GPU compositing text clarity in WebKitGTK

Use on-demand hardware acceleration on main and mini webviews when the
session is Wayland and compositing stays on; gate subpixel body AA on the
same conditions via new Tauri probes. Document PSYSONIC_SKIP_WAYLAND_FONT_TUNING
for opt-out and changelog.

* fix(rust): satisfy clippy needless_return in Linux webkit helpers

* fix(linux): tune Wayland text rendering with HW policy env and CSS

Allow PSYSONIC_WEBKIT_WAYLAND_HW_POLICY to select WebKit hardware
acceleration policy (never/always vs default on-demand). Extend Wayland
font CSS to #root with geometricPrecision and text-size-adjust on html.

* feat(linux): Wayland text presets in settings, safe WebKit apply, CPU default

Persist profile to app config; apply WebKit policy at startup/mini only to
avoid WebKitGTK hangs on live toggles. UI + CSS preview stays live; default
preset is sharp (CPU-friendly).

* fix(linux): map Wayland sharp preset to OnDemand WebKit policy

HardwareAccelerationPolicy::Never at startup broke main-viewport wheel
scrolling on WebKitGTK+Wayland; sharp vs balanced remains a CSS AA path.
Use PSYSONIC_WEBKIT_WAYLAND_HW_POLICY for a true Never policy.

* fix(rust): gate Linux-only Wayland WebKit helpers for Windows builds

Re-export startup helpers only under cfg(linux) and drop non-Linux stubs so
Windows compiles without unused-import and dead-code warnings.

* chore(release): CHANGELOG + credits for Linux session/WebKit work (PR #731)

Consolidate scattered incremental changelog notes into two [1.47.0]
entries with PR link; remove duplicate Linux blocks from [1.46.0] Fixed.
Append settings credit line for cucadmuh.

src-tauri/src/lib_commands/sync/mod.rs

@@ -1,7 +1,7 @@
 mod tray;
 
 pub(crate) use tray::{
-    is_tiling_wm_cmd, no_compositing_mode, set_tray_menu_labels, set_tray_tooltip,
+    is_tiling_wm_cmd, linux_xdg_session_type, no_compositing_mode, set_tray_menu_labels, set_tray_tooltip,
     toggle_tray_icon,
 };
 // Internal helpers consumed elsewhere in the shell crate:

src-tauri/src/lib_commands/sync/tray.rs

@@ -398,6 +398,20 @@ pub(crate) fn no_compositing_mode() -> bool {
         .unwrap_or(false)
 }
 
+/// Tauri command: `XDG_SESSION_TYPE` from the host environment (e.g. `wayland`, `x11`).
+/// Used for Linux-only UI tweaks such as font rasterisation hints; empty string when unset.
+#[tauri::command]
+pub(crate) fn linux_xdg_session_type() -> String {
+    #[cfg(target_os = "linux")]
+    {
+        std::env::var("XDG_SESSION_TYPE").unwrap_or_default()
+    }
+    #[cfg(not(target_os = "linux"))]
+    {
+        String::new()
+    }
+}
+
 #[cfg(not(target_os = "linux"))]
 pub(crate) fn is_tiling_wm() -> bool {
     false