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/session/sidebar/SessionGroupSection.tsx

@@ -165,26 +165,32 @@ export function SessionGroupSection(props: Props): React.ReactNode {
     [compareSessionNodes, group.sessions, searchData?.filteredNodes, shouldFilterGroupContents],
   );
   const folderScopeKey = group.folderScopeKey ?? normalizePath(group.directory ?? null);
-  const scopeFolders = folderScopeKey ? getFoldersForScope(folderScopeKey) : [];
+  const scopeFolders = React.useMemo(
+    () => folderScopeKey ? getFoldersForScope(folderScopeKey) : [],
+    [folderScopeKey, getFoldersForScope]
+  );
 
-  const nodeBySessionId = new Map<string, SessionNode>();
-  const collectNodeLookup = (nodes: SessionNode[]) => {
-    nodes.forEach((node) => {
-      nodeBySessionId.set(node.session.id, node);
-      if (node.children.length > 0) {
-        collectNodeLookup(node.children);
-      }
-    });
-  };
-  collectNodeLookup(sourceGroupNodes);
+  const nodeBySessionId = React.useMemo(() => {
+    const map = new Map<string, SessionNode>();
+    const collectNodeLookup = (nodes: SessionNode[]) => {
+      nodes.forEach((node) => {
+        map.set(node.session.id, node);
+        if (node.children.length > 0) {
+          collectNodeLookup(node.children);
+        }
+      });
+    };
+    collectNodeLookup(sourceGroupNodes);
+    return map;
+  }, [sourceGroupNodes]);
 
-  const allFoldersForGroupBase = scopeFolders.map((folder) => {
+  const allFoldersForGroupBase = React.useMemo(() => scopeFolders.map((folder) => {
     const nodes = folder.sessionIds
       .map((sid) => nodeBySessionId.get(sid))
       .filter((n): n is SessionNode => Boolean(n))
       .sort(compareSessionNodes);
     return { folder, nodes };
-  });
+  }), [scopeFolders, nodeBySessionId, compareSessionNodes]);
 
   const allFoldersForGroup = React.useMemo(() => {
     const folderMapById = new Map(allFoldersForGroupBase.map((entry) => [entry.folder.id, entry]));
@@ -238,9 +244,9 @@ export function SessionGroupSection(props: Props): React.ReactNode {
     return allFoldersForGroupBase.filter(({ folder }) => shouldKeepFolder(folder.id));
   }, [allFoldersForGroupBase, group.isArchivedBucket, hasSessionSearchQuery, normalizedSessionSearchQuery]);
 
-  const sessionIdsInFolders = new Set(allFoldersForGroup.flatMap((f) => f.folder.sessionIds));
-  const ungroupedSessions = sourceGroupNodes.filter((node) => !sessionIdsInFolders.has(node.session.id));
-  const rootFolders = allFoldersForGroup.filter(({ folder }) => !folder.parentId);
+  const sessionIdsInFolders = React.useMemo(() => new Set(allFoldersForGroup.flatMap((f) => f.folder.sessionIds)), [allFoldersForGroup]);
+  const ungroupedSessions = React.useMemo(() => sourceGroupNodes.filter((node) => !sessionIdsInFolders.has(node.session.id)), [sourceGroupNodes, sessionIdsInFolders]);
+  const rootFolders = React.useMemo(() => allFoldersForGroup.filter(({ folder }) => !folder.parentId), [allFoldersForGroup]);
 
   if (hasSessionSearchQuery && !groupMatchesSearch && rootFolders.length === 0 && ungroupedSessions.length === 0) {
     return null;