perf(app): keep warm workspace switching responsive (#3447)

* perf(app): reduce warm workspace switch work

Retained workspaces avoided mounts but pane activity still rerendered the full composer, message input, and agent-control presentation. Keep the activity contract intact while moving focus-sensitive behavior behind small context consumers, and add a Playwright benchmark that measures rapid retained workspace switching on one browser clock.

* perf(app): accelerate retained workspace switching

Avoid repeated retained-stream layout reconciliation and unrelated workspace structure recomputation. Use the lightweight route transition while the host is already focused, while preserving targeted root POP_TO for returns from app-wide routes where it prevents duplicate hidden decks.

* perf(app): defer composer focus during workspace switches

* perf(app): retain recently used workspaces longer

Keep up to ten workspace screens warm so normal multi-workspace navigation does not repeatedly rebuild recently used timelines. Inactive screens expire after ten minutes, while the active screen remains protected and capacity eviction stays least-recently-used.

* fix(app): reconcile retained timeline geometry

* fix(app): refresh retained reading position

packages/app/src/composer/input/input.tsx

@@ -54,6 +54,7 @@ import type { MessageInputKeyboardActionKind } from "@/keyboard/actions";
 import { isImeComposingKeyboardEvent } from "@/utils/keyboard-ime";
 import { isWeb } from "@/constants/platform";
 import { useIsCompactFormFactor } from "@/constants/layout";
+import { useComposerKeyboardScope } from "@/composer/keyboard-scope";
 import { useComposerHeightMirror } from "./height-mirror";
 import { resolveComposerInputMode, type ComposerInputMode } from "@/composer/input-mode";
 import type { NativePastedFile } from "@/composer/native-pasted-image";
@@ -116,8 +117,6 @@ export interface MessageInputProps {
   autoFocus?: boolean;
   autoFocusKey?: string;
   disabled?: boolean;
-  /** True when this composer's pane is focused. Used to gate global hotkeys and stop dictation when hidden. */
-  isPaneFocused?: boolean;
   /** Content to render on the left side of the composer toolbar (e.g., AgentControls) */
   leftContent?: React.ReactNode;
   /** Content to render on the right side before the voice button (e.g., context window meter) */
@@ -496,11 +495,26 @@ function useAutoFocusOnWebEffect(
         const active = typeof document !== "undefined" ? document.activeElement : null;
         return Boolean(element) && active === element;
       },
+      deferInitialAttempt: true,
     });
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [autoFocus, autoFocusKey]);
 }
 
+function MessageInputAutoFocus({
+  enabled,
+  autoFocusKey,
+  textInputRef,
+}: {
+  enabled: boolean;
+  autoFocusKey: string | undefined;
+  textInputRef: React.MutableRefObject<ComposerTextInputHandle | null>;
+}) {
+  const { isActiveComposer } = useComposerKeyboardScope();
+  useAutoFocusOnWebEffect(textInputRef, enabled && isActiveComposer, autoFocusKey);
+  return null;
+}
+
 function MessageInputOverlay({
   showDictationOverlay,
   showRealtimeOverlay,
@@ -580,7 +594,8 @@ function FocusHint({
   focusInputKeys: ShortcutChord | null | undefined;
   label: string;
 }) {
-  if (!visible || !focusInputKeys || !label.trim()) return null;
+  const { isActiveComposer } = useComposerKeyboardScope();
+  if (!isActiveComposer || !visible || !focusInputKeys || !label.trim()) return null;
   return (
     <Text style={styles.focusHintText} pointerEvents="none">
       {label}
@@ -1030,7 +1045,6 @@ interface ResolvedMessageInputProps {
   autoFocus: boolean;
   autoFocusKey: string | undefined;
   disabled: boolean;
-  isPaneFocused: boolean;
   leftContent: React.ReactNode;
   beforeVoiceContent: React.ReactNode;
   rightContent: React.ReactNode;
@@ -1078,7 +1092,6 @@ function resolveMessageInputProps(props: MessageInputProps): ResolvedMessageInpu
     autoFocus: props.autoFocus ?? false,
     autoFocusKey: props.autoFocusKey,
     disabled: props.disabled ?? false,
-    isPaneFocused: props.isPaneFocused ?? true,
     leftContent: props.leftContent,
     beforeVoiceContent: props.beforeVoiceContent,
     rightContent: props.rightContent,
@@ -1134,7 +1147,6 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
       autoFocus,
       autoFocusKey,
       disabled,
-      isPaneFocused,
       leftContent,
       beforeVoiceContent,
       rightContent,
@@ -1237,8 +1249,6 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
       };
     }, [onFocusChange]);
 
-    useAutoFocusOnWebEffect(textInputRef, autoFocus, autoFocusKey);
-
     const handleDictationTranscript = useCallback(
       (text: string, _meta: { requestId: string }) => {
         const autoSend = sendAfterTranscriptRef.current;
@@ -1738,6 +1748,11 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
 
     return (
       <View ref={rootRef} style={styles.container} testID="message-input-root">
+        <MessageInputAutoFocus
+          enabled={autoFocus}
+          autoFocusKey={autoFocusKey}
+          textInputRef={textInputRef}
+        />
         {/* Regular input */}
         <View
           ref={inputWrapperRef}
@@ -1759,13 +1774,13 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
             onBlur={handleInputBlur}
             editable={!isDictating && !isRealtimeVoiceForCurrentAgent && !disabled}
             scrollEnabled={isWeb ? inputHeight >= maxInputHeight : true}
-            autoFocus={isWeb && autoFocus}
+            autoFocus={false}
             onContentSizeChange={handleContentSizeChange}
             onKeyPress={shouldHandleWebKeyPress ? handleDesktopKeyPress : undefined}
             onSelectionChange={handleSelectionChange}
             onPasteImages={onPasteImages}
             onPasteError={handlePasteError}
-            focusHintVisible={isWeb && isPaneFocused && !isInputFocused && !value}
+            focusHintVisible={isWeb && !isInputFocused && !value}
             focusInputKeys={focusInputKeys}
             focusHintLabel={t("composer.input.focusHint", {
               shortcut: focusInputKeys ? formatShortcut(focusInputKeys[0], getShortcutOs()) : "",