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/views/agent-manager/AgentManagerEmptyState.tsx

@@ -456,11 +456,14 @@ export const AgentManagerEmptyState: React.FC<AgentManagerEmptyStateProps> = ({
           <CollapsibleTrigger className="w-full flex items-center justify-between py-1 hover:bg-[var(--interactive-hover)] rounded-md px-1 -mx-1 transition-colors">
             <p className="typography-ui-label font-medium text-foreground">
               {t('agentManager.empty.setupCommands.label')}
-              {setupCommands.filter(cmd => cmd.trim()).length > 0 && (
-                <span className="font-normal text-muted-foreground/70">
-                  {' '}({t('agentManager.empty.setupCommands.configured', { count: setupCommands.filter(cmd => cmd.trim()).length })})
-                </span>
-              )}
+              {(() => {
+                const trimmedCommandCount = setupCommands.filter(cmd => cmd.trim()).length;
+                return trimmedCommandCount > 0 ? (
+                  <span className="font-normal text-muted-foreground/70">
+                    {' '}({t('agentManager.empty.setupCommands.configured', { count: trimmedCommandCount })})
+                  </span>
+                ) : null;
+              })()}
             </p>
             <RiArrowDownSLine className={cn(
               'h-4 w-4 text-muted-foreground transition-transform duration-200',