Plug three holes in Servo input forwarding

1. Scroll no longer wipes keyboard focus. Servo holds DOM focus across
   wheel events; the shell was clearing keyboard_focus and typed_texts
   on every scroll, so a focused input went deaf the moment the user
   scrolled. Scroll still drops the buffered click point because that
   coordinate is captured against the pre-scroll viewport.

2. Mouse-down hands focus to the shell's root focus handle (in
   addition to mouse-up's existing click forwarding). The user can now
   start typing the moment they press the page, instead of having to
   first complete a click round-trip to escape the omnibar's focus.

3. Sidecar hover() honors the requesting webview_id instead of
   defaulting to the first webview in the map, so multi-tab sidecars
   no longer pipe every hover into tab #1.

crates/ely_servo_host/src/bin/ely_servo_sidecar/live.rs

@@ -9,9 +9,9 @@ use std::{
 
 use ely_domain::{DEFAULT_ZOOM_PERCENT, ProfileId, TabId, UrlText};
 use ely_servo_host::{
-    KeyboardTextRequest, MouseClickRequest, NavigationRequest, PageZoomRequest, PermissionDecision,
-    PermissionRequest, RenderedFrame, ResizeRequest, ScrollRequest, ServoHost, ServoHostError,
-    ServoSurfaceSize, SoftwareServoHost, WebViewSnapshot, WebViewState,
+    KeyboardTextRequest, MouseClickRequest, MouseHoverRequest, NavigationRequest, PageZoomRequest,
+    PermissionDecision, PermissionRequest, RenderedFrame, ResizeRequest, ScrollRequest, ServoHost,
+    ServoHostError, ServoSurfaceSize, SoftwareServoHost, WebViewSnapshot, WebViewState,
 };
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
@@ -230,7 +230,7 @@ fn apply_input(
     }
 
     if let (Some(x), Some(y)) = (hover_x, hover_y) {
-        host.hover(x, y)?;
+        host.hover(MouseHoverRequest { webview_id: session.webview_id.clone(), x, y })?;
         changed = true;
     }
 

crates/ely_servo_host/src/host.rs

@@ -242,6 +242,13 @@ pub struct MouseClickRequest {
     pub y: u32,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct MouseHoverRequest {
+    pub webview_id: WebViewId,
+    pub x: u32,
+    pub y: u32,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct MouseDragRequest {
     pub webview_id: WebViewId,

crates/ely_servo_host/src/lib.rs

@@ -15,9 +15,10 @@ mod runtime_webview;
 
 pub use error::ServoHostError;
 pub use host::{
-    KeyboardTextRequest, MouseClickRequest, MouseDragRequest, NavigationRequest, PageZoomRequest,
-    PermissionDecision, PermissionRequest, RenderedFrame, RenderedFrameSummary, ResizeRequest,
-    ScreenshotRequest, ScrollRequest, ServoHost, TouchTapRequest, WebViewSnapshot, WebViewState,
+    KeyboardTextRequest, MouseClickRequest, MouseDragRequest, MouseHoverRequest,
+    NavigationRequest, PageZoomRequest, PermissionDecision, PermissionRequest, RenderedFrame,
+    RenderedFrameSummary, ResizeRequest, ScreenshotRequest, ScrollRequest, ServoHost,
+    TouchTapRequest, WebViewSnapshot, WebViewState,
 };
 #[cfg(feature = "servo-engine")]
 pub use runtime::{ServoSurfaceSize, SoftwareServoHost};

crates/ely_servo_host/src/runtime.rs

@@ -20,9 +20,10 @@ use servo::{
 use url::Url;
 
 use crate::{
-    KeyboardTextRequest, MouseClickRequest, MouseDragRequest, NavigationRequest, PageZoomRequest,
-    PermissionDecision, PermissionRequest, RenderedFrame, ResizeRequest, ScreenshotRequest,
-    ScrollRequest, ServoHost, ServoHostError, TouchTapRequest, WebViewSnapshot, WebViewState,
+    KeyboardTextRequest, MouseClickRequest, MouseDragRequest, MouseHoverRequest,
+    NavigationRequest, PageZoomRequest, PermissionDecision, PermissionRequest, RenderedFrame,
+    ResizeRequest, ScreenshotRequest, ScrollRequest, ServoHost, ServoHostError, TouchTapRequest,
+    WebViewSnapshot, WebViewState,
     runtime_input::{
         send_keyboard_text, send_mouse_click, send_mouse_drag, send_mouse_hover, send_touch_tap,
     },
@@ -196,10 +197,13 @@ impl ServoHost for SoftwareServoHost {
         Ok(())
     }
 
-    fn hover(&mut self, x: u32, y: u32) -> Result<(), ServoHostError> {
-        if let Some(webview) = self.webviews.values().next() {
-            send_mouse_hover(&webview.webview, x, y);
-        }
+    fn hover(&mut self, request: MouseHoverRequest) -> Result<(), ServoHostError> {
+        let webview = self
+            .webviews
+            .get(&request.webview_id)
+            .ok_or_else(|| ServoHostError::WebViewNotFound { id: request.webview_id.clone() })?;
+
+        send_mouse_hover(&webview.webview, request.x, request.y);
         Ok(())
     }