Wayland backend: desktop icons v2, menu rebuild, layer-shell/scale fixes,

XWayland stability, GPU rendering, and multi-cursor Phase 2

The bulk of a multi-session shift's real work landed in crates/wayland.
Full root-cause/verification narrative for every item below lives in
docs/TODO.md (each has its own dated entry); this is the summary:

Desktop shell:
- Real desktop icons v2 (state/desktop_icons.rs, desktop_icons.rs):
  fixed origin-baked-before-the-bar-connects, fixed-icon sort order, and
  a proper Rename/Delete-to-Trash menu (window_memory.rs backs the
  rename-persistence side). Rubber-band marquee multi-select.
- icon_theme.rs: real freedesktop icon-theme lookup (inherits chain,
  hicolor fallback) rendering actual theme SVGs via resvg/tiny-skia,
  replacing the hand-drawn placeholder glyphs.
- Context/desktop menus (decoration.rs, desktop_menu.rs, state/menu.rs)
  rebuilt to match the project's own AGS panel styling: rounded floating
  panel, tinted-fill row highlight, real separators, a much fuller
  titlebar window-menu action set.

Layer-shell / multi-monitor:
- Layer-shell hit-testing and render positioning (input/pointer.rs,
  udev/render.rs's element placement) now correctly convert LayerMap's
  logical geometry into physical pixels on a fractionally-scaled output
  - root cause of a bottom-anchored dock being unclickable and
  unpainted while a top-anchored bar on the same output worked.
  udev/outputs.rs's relayout_outputs gained the same physical/logical
  split for cross-output positioning, now backed by a real unit test
  (next_logical_x) built from the original measured incident numbers.
- state/geometry.rs: a window's border/decoration no longer briefly
  clips when moved between differently-scaled monitors mid-drag.

XWayland / stability:
- xwayland.rs, udev/session.rs, udev/platform.rs: fixed a 100%-
  reproducible cold-start XKEYBOARD crash-loop (XWayland's own stdin
  inherited a real, already-owned VT; env passthrough and idle-callback
  spawn timing were both real, independent gaps) that had silently taken
  down all X11-app support and the global-menu registrar every session.
- state/toplevel.rs, state/lifecycle.rs: XWayland dialog detection via
  WM_TRANSIENT_FOR, not just a native xdg_toplevel parent.

Rendering:
- udev/render.rs, decoration.rs: real GPU (GBM+EGL+DrmCompositor)
  window-content and cursor rendering on the udev backend, falling back
  to the untouched Pixman path automatically on any init failure.
- decoration/tests.rs, state/mod.rs: rounded-corner/border fixes for
  interactive resize lag and cross-monitor moves.

Multi-cursor Phase 2 (virtual_pointer.rs, new; state/mod.rs, udev/
platform.rs, winit/nested_platform.rs): pins a zwlr_virtual_pointer_
unstable_v1 object to a specific window, bypassing the shared seat/
focus/pointer_pos path entirely via hand-rolled wl_pointer.enter/motion/
button/frame/leave against every WlPointer the target client has bound
(PointerHandle::client_pointers). Lets an agent operate one window while
a human uses another, genuinely simultaneously, with zero client
cooperation and no second wl_seat (confirmed a dead end: real clients
only ever bind the first seat advertised).

Full workspace build/test/clippy clean.

1 files changed, 16 insertions, 1 deletions

diff --git a/crates/wayland/src/udev/mod.rs b/crates/wayland/src/udev/mod.rs
index d22666d..27a7c2c 100644
--- a/crates/wayland/src/udev/mod.rs
+++ b/crates/wayland/src/udev/mod.rs
@@ -204,6 +204,21 @@ pub(crate) struct UdevState {
     /// Pointer position in the *global* space, so it can cross between
     /// monitors; clamped to the union of all head rectangles.
     pub(crate) pointer_pos: Point<f64, Logical>,
+    /// Multi-cursor mode, Phase 1: every physical pointer/trackpad's own
+    /// last-known position, keyed by its real libinput device identity
+    /// (`smithay::backend::input::Event::device()`, confirmed `Device:
+    /// PartialEq + Eq + Hash` by reading smithay's own trait definition).
+    /// Purely a *visual* addition - `pointer_pos` above is still the one
+    /// position that actually drives clicks/drags/hit-testing, updated by
+    /// whichever device moved most recently exactly as before, so nothing
+    /// about existing interactive behaviour changes. This is what lets a
+    /// mouse and a trackpad each show their own live cursor sprite instead
+    /// of only the most-recently-moved device having a visible pointer at
+    /// all - see `docs/TODO.md`'s "Multi-cursor" plan for what later
+    /// phases would still need (per-device *interaction*, not just
+    /// per-device *rendering*, and the real `wl_seat` ecosystem wall a
+    /// second seat runs into for arbitrary client content).
+    pub(crate) secondary_cursors: HashMap<smithay::reexports::input::Device, Point<f64, Logical>>,
     /// A clone of the same `LibSeatSession` `platform.rs` opened the DRM
     /// device with (`LibSeatSession` is cheaply `Clone` - see its own
     /// derive - all clones share the same underlying seat connection).
@@ -267,7 +282,7 @@ impl UdevState {
     /// this from outside, but srdwm's own pointer clamp assuming an origin
     /// no other part of this backend actually enforces is the real bug --
     /// fixed here instead of just left for every future caller to avoid.
-    fn bounds(&self) -> (f64, f64, f64, f64) {
+    pub(crate) fn bounds(&self) -> (f64, f64, f64, f64) {
         bounds_of(self.heads.iter().map(|h| (h.location.x, h.location.y, h.size.0, h.size.1)))
     }
 }