Keep reconnecting and updating status visible in native chats (#8568)

* fix(app): keep chat status toasts visible below floating headers

Compact native chats extend beneath the floating header. Panel toasts need measured header clearance and a layer above its fade; placing them below the fade leaves an excessive gap. Keep dock overlays outside keyboard translation so opening the keyboard cannot move them offscreen.

* test(app): verify rendered chat status spacing on native devices

Measure the real header and toast bounds with the software keyboard closed and open. The former arithmetic helper test passed even when the viewport stopped consuming header clearance; the native regression fails against that broken production wiring.

* test(app): exercise toast placement through host disconnection

Observe the public reconnecting state with host connectivity interrupted externally. Keep native bounds and software keyboard assertions while removing runtime evaluation and private timeline-owner mutations.

(cherry picked from commit b92a34ab3d)

packages/app/src/components/floating-header/index.tsx

@@ -1,8 +1,26 @@
-import { useCallback, useState, type ReactNode } from "react";
+import { createContext, useContext, useCallback, useState, useId, type ReactNode } from "react";
 import { View, type LayoutChangeEvent } from "react-native";
 import { StyleSheet } from "react-native-unistyles";
+import { Portal, PortalHost } from "@gorhom/portal";
+import { useRetainedPanelActive } from "@/components/retained-panel";
 import { EdgeFade } from "@/components/ui/edge-fade";
 
+const OverlayClearanceContext = createContext(0);
+const OverlayHostContext = createContext<string | null>(null);
+
+/** Keep status overlays above the fade without lifting the scrolling content. */
+export function FloatingHeaderOverlay({ children }: { children: ReactNode }) {
+  const hostName = useContext(OverlayHostContext);
+  const active = useRetainedPanelActive();
+  if (!hostName) return children;
+  return active ? <Portal hostName={hostName}>{children}</Portal> : null;
+}
+
+/** Clearance for stationary overlays inside this layout, measured to the header bottom. */
+export function useFloatingHeaderOverlayClearance(): number {
+  return useContext(OverlayClearanceContext);
+}
+
 /** How far the fade runs past the header's bottom edge, so content dissolves instead of clipping. */
 const FADE_OVERHANG = 48;
 /** Share of the fade that stays opaque, so the header's title and icons keep contrast. */
@@ -20,15 +38,24 @@ interface FloatingHeaderLayoutProps {
  * same tree position in both modes, so toggling `floating` never remounts them.
  */
 export function FloatingHeaderLayout({ header, floating, children }: FloatingHeaderLayoutProps) {
+  const overlayHostName = useId();
   const [headerHeight, setHeaderHeight] = useState(0);
   const handleHeaderLayout = useCallback((event: LayoutChangeEvent) => {
     setHeaderHeight(Math.round(event.nativeEvent.layout.height));
   }, []);
 
+  const overlayClearance = floating ? headerHeight : 0;
+
   return (
     <View style={styles.root}>
       {floating ? null : header}
-      <View style={styles.content}>{children(floating ? headerHeight : 0)}</View>
+      <View style={styles.content}>
+        <OverlayClearanceContext.Provider value={overlayClearance}>
+          <OverlayHostContext.Provider value={floating ? overlayHostName : null}>
+            {children(floating ? headerHeight : 0)}
+          </OverlayHostContext.Provider>
+        </OverlayClearanceContext.Provider>
+      </View>
       {floating ? (
         <View style={styles.overlay} pointerEvents="box-none">
           <EdgeFade
@@ -37,11 +64,19 @@ export function FloatingHeaderLayout({ header, floating, children }: FloatingHea
             backdrop="surfaceWorkspace"
             style={styles.fade}
           />
-          <View pointerEvents="box-none" onLayout={handleHeaderLayout}>
+          <View
+            testID="floating-header"
+            collapsable={false}
+            pointerEvents="box-none"
+            onLayout={handleHeaderLayout}
+          >
             {header}
           </View>
         </View>
       ) : null}
+      <View style={styles.statusOverlay} pointerEvents="box-none">
+        <PortalHost name={overlayHostName} />
+      </View>
     </View>
   );
 }
@@ -55,6 +90,13 @@ const styles = StyleSheet.create({
     flex: 1,
     minHeight: 0,
   },
+  statusOverlay: {
+    position: "absolute",
+    top: 0,
+    bottom: 0,
+    left: 0,
+    right: 0,
+  },
   overlay: {
     position: "absolute",
     top: 0,