chore(desktop): zero eslint/typecheck debt + prettier pass (#39100)

- eslint --fix across src/ and electron/ (unused imports, import/prop sort, padding)
- flatten empty catch blocks in electron CJS; drop unused applyUpdatesPosixInApp arg
- add setMutableRef helper for imperative ref writes (react-compiler clean)
- move sidebar cookie persistence into an effect; extract scrollElementToBottom helper

apps/desktop/src/app/chat/composer/context-menu.tsx

@@ -2,13 +2,7 @@ import { useState } from 'react'
 
 import { Button } from '@/components/ui/button'
 import { Codicon } from '@/components/ui/codicon'
-import {
-  Dialog,
-  DialogContent,
-  DialogDescription,
-  DialogHeader,
-  DialogTitle
-} from '@/components/ui/dialog'
+import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from '@/components/ui/dialog'
 import {
   DropdownMenu,
   DropdownMenuContent,
@@ -104,8 +98,8 @@ export function ContextMenu({
           <DropdownMenuSeparator />
 
           <div className="px-2 py-1 text-[0.7rem] text-muted-foreground/80">
-            Tip: type <kbd className="rounded bg-muted/70 px-1 py-px font-mono text-[0.65rem]">@</kbd> to reference files
-            inline.
+            Tip: type <kbd className="rounded bg-muted/70 px-1 py-px font-mono text-[0.65rem]">@</kbd> to reference
+            files inline.
           </div>
         </DropdownMenuContent>
       </DropdownMenu>
@@ -120,12 +114,7 @@ export function ContextMenu({
   )
 }
 
-function PromptSnippetsDialog({
-  onInsertText,
-  onOpenChange,
-  open,
-  snippets
-}: PromptSnippetsDialogProps) {
+function PromptSnippetsDialog({ onInsertText, onOpenChange, open, snippets }: PromptSnippetsDialogProps) {
   return (
     <Dialog onOpenChange={onOpenChange} open={open}>
       <DialogContent className="max-w-md gap-3">
@@ -160,12 +149,7 @@ function PromptSnippetsDialog({
   )
 }
 
-export function ContextMenuItem({
-  children,
-  disabled,
-  icon: Icon,
-  onSelect
-}: ContextMenuItemProps) {
+export function ContextMenuItem({ children, disabled, icon: Icon, onSelect }: ContextMenuItemProps) {
   return (
     <DropdownMenuItem disabled={disabled} onSelect={onSelect}>
       <Icon />

apps/desktop/src/app/chat/composer/index.tsx

@@ -21,11 +21,7 @@ import { chatMessageText } from '@/lib/chat-messages'
 import { DATA_IMAGE_URL_RE } from '@/lib/embedded-images'
 import { triggerHaptic } from '@/lib/haptics'
 import { cn } from '@/lib/utils'
-import {
-  $composerAttachments,
-  clearComposerAttachments,
-  type ComposerAttachment
-} from '@/store/composer'
+import { $composerAttachments, clearComposerAttachments, type ComposerAttachment } from '@/store/composer'
 import {
   $queuedPromptsBySession,
   enqueueQueuedPrompt,
@@ -172,7 +168,7 @@ export function ChatBar({
   const [queueEdit, setQueueEdit] = useState<QueueEditState | null>(null)
   const [focusRequestId, setFocusRequestId] = useState(0)
   const dragDepthRef = useRef(0)
-  const composingRef = useRef(false)  // true during IME composition (CJK input)
+  const composingRef = useRef(false) // true during IME composition (CJK input)
   const lastSpokenIdRef = useRef<string | null>(null)
 
   const narrow = useMediaQuery('(max-width: 30rem)')
@@ -1253,9 +1249,11 @@ export function ChatBar({
           onDrop={handleDrop}
           onSubmit={e => {
             e.preventDefault()
+
             if (composingRef.current) {
               return
             }
+
             submitDraft()
           }}
           ref={composerRef}

apps/desktop/src/app/chat/composer/slash-nav-dom-repro.test.tsx

@@ -37,7 +37,10 @@ function Harness({
   const refreshTrigger = useCallback(() => {
     const editor = editorRef.current
 
-    if (!editor) {return}
+    if (!editor) {
+      return
+    }
+
     const raw = editor.textContent ?? ''
 
     if (!raw.includes('@') && !raw.includes('/')) {