Scope redraw requests and avoid redundant animation fallback wakeups

Instrument redraw sources, per-output request coalescing, and animation fallback scheduling. Route local visual changes to their affected outputs while preserving deferred grab and gesture updates.

Schedule fallback recovery using each orphaned animation output's refresh interval, suppress it while a normal frame chain exists, and retain requested final frames after scheduling failures. Add mixed-refresh, cursor footprint, frame-chain, and disconnect regressions and document measurement limits.

compositor/src/handlers/layer_shell.rs

@@ -32,8 +32,7 @@ impl WlrLayerShellHandler for Ferese {
 
         tracing::debug!(%namespace, output = %output.name(), "mapped layer surface");
         super::set_surface_tree_output(layer.wl_surface(), &output);
-        self.relayout();
-        crate::backends::direct::render_all(self);
+        self.relayout_on(&[output]);
     }
 
     fn new_popup(&mut self, parent: LayerSurface, popup: PopupSurface) {
@@ -59,17 +58,22 @@ impl WlrLayerShellHandler for Ferese {
             return;
         };
         let restore_focus = layer_has_keyboard_focus(self, &layer);
-        let outputs = self.space.outputs().cloned().collect::<Vec<_>>();
+        let outputs = self
+            .space
+            .outputs()
+            .filter(|output| layer_map_for_output(output).layer_geometry(&layer).is_some())
+            .cloned()
+            .collect::<Vec<_>>();
 
-        for output in outputs {
-            layer_map_for_output(&output).unmap_layer(&layer);
+        for output in &outputs {
+            layer_map_for_output(output).unmap_layer(&layer);
         }
 
-        self.relayout();
+        self.relayout_on(&outputs);
         if restore_focus {
             self.restore_keyboard_focus();
         }
-        crate::backends::direct::render_all(self);
+        crate::backends::direct::render_on(self, &outputs);
     }
 }
 
@@ -77,10 +81,15 @@ pub fn handle_commit(state: &mut Ferese, surface: &WlSurface) {
     let Some(layer) = state.space.layer_for_surface(surface, WindowSurfaceType::TOPLEVEL) else {
         return;
     };
-    let outputs = state.space.outputs().cloned().collect::<Vec<_>>();
+    let outputs = state
+        .space
+        .outputs()
+        .filter(|output| layer_map_for_output(output).layer_geometry(&layer).is_some())
+        .cloned()
+        .collect::<Vec<_>>();
 
-    for output in outputs {
-        let mut map = layer_map_for_output(&output);
+    for output in &outputs {
+        let mut map = layer_map_for_output(output);
         if map.layer_geometry(&layer).is_some() {
             map.arrange();
             layer.layer_surface().send_pending_configure();
@@ -103,7 +112,7 @@ pub fn handle_commit(state: &mut Ferese, surface: &WlSurface) {
         state.restore_keyboard_focus();
     }
 
-    state.relayout();
+    state.relayout_on(&outputs);
     if let Err(error) = state.display_handle.flush_clients() {
         tracing::debug!(%error, "failed to flush layer-surface configure");
     }