perf: reduce re-renders, fix mobile keyboard handling, add chunk load recovery, and improve PATH management (#1028)

* fix: exclude file content from reverted prompt text

Revert and fork now restore only the user's original prompt, not server-injected file content
Uses existing isSyntheticPart helper for type-safe filtering

* fix: keep scrollbar visible when hovering over thumb

* fix: prevent ESC abort from triggering when terminal is focused

* fix: pass directory to permission/question reply calls so approvals actually resolve

* fix: default model selection not responding after Base UI migration

* fix: prevent modal content from shifting and clipping footer buttons

* fix: improve session switching performance and add sub-agent export with prompt collapse

Defer viewport anchor saving to eliminate ~800ms UI freeze when switching sessions
Add export dialog to include sub-agent tasks recursively in markdown export
Add collapse chevron button for expanded user prompts in sticky header

* fix: resolve sidebar scroll and TDZ crash in session sidebar

* perf: reduce CPU overhead and re-renders across chat, layout, and settings

* fix: position collapse button at top of message and prevent ESC abort in terminal

* fix: position collapse button at top and add padding only when expanded

* refactor: extract shared PATH utilities and mobile keyboard hook

* refactor: import shared path-utils in electron, use module-level style constants

- Electron now imports pathLooksUserConfigured/mergePathValues from
  shared path-utils.js instead of inline duplication
- ToolPart collapsedCustomStyle moved from useMemo([]) to module const

* fix: resolve remaining merge conflicts and type errors

- Remove duplicate variable declarations in SessionNodeItem
- Remove orphaned export callback body from conflict resolution
- Fix HelpDialog description -> descriptionKey (i18n rename)

* fix: resolve type-check and lint errors in session-actions.test.ts

- Added missing bun:test type declarations (beforeEach, mock, mock.module)
- Removed unused State import
- Replaced 'as any' casts with proper OpencodeClient and ChildStoreManager types
- Added eslint-disable for unused _ parameter in mock function

* fix PR 1028 export and PATH edge cases

* fix startup retry exhaustion state

* remove opencode package lock change

* fix sub-session rename cancellation

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/components/chat/hooks/useChatTimelineController.ts

@@ -120,41 +120,15 @@ export const useChatTimelineController = ({
 
     const historySignalsRef = React.useRef(historySignals);
 
-    React.useEffect(() => {
-        turnModelRef.current = turnWindowModel;
-    }, [turnWindowModel]);
-
-    React.useEffect(() => {
-        turnStartRef.current = turnStart;
-    }, [turnStart]);
-
-    React.useEffect(() => {
-        isPinnedRef.current = isPinned;
-    }, [isPinned]);
-
-    React.useEffect(() => {
-        isLoadingOlderRef.current = isLoadingOlder;
-    }, [isLoadingOlder]);
-
-    React.useEffect(() => {
-        pendingRevealWorkRef.current = pendingRevealWork;
-    }, [pendingRevealWork]);
-
-    React.useEffect(() => {
-        historySignalsRef.current = historySignals;
-    }, [historySignals]);
-
-    React.useEffect(() => {
-        sessionIdRef.current = sessionId;
-    }, [sessionId]);
-
-    React.useEffect(() => {
-        messagesRef.current = messages;
-    }, [messages]);
-
-    React.useEffect(() => {
-        historyMetaRef.current = historyMeta;
-    }, [historyMeta]);
+    turnModelRef.current = turnWindowModel;
+    turnStartRef.current = turnStart;
+    isPinnedRef.current = isPinned;
+    isLoadingOlderRef.current = isLoadingOlder;
+    pendingRevealWorkRef.current = pendingRevealWork;
+    historySignalsRef.current = historySignals;
+    sessionIdRef.current = sessionId;
+    messagesRef.current = messages;
+    historyMetaRef.current = historyMeta;
 
     React.useLayoutEffect(() => {
         if (initializedSessionRef.current === sessionId) {