fix: preserve folder upload mode across refresh (#551) (thanks @MunemHashmi)

Replace the useEffect + useRef approach for setting webkitdirectory/
directory attributes with a ref callback that sets the attributes
every time the input element is mounted. This ensures folder selection
mode persists after page refresh, where React hydration could strip
the non-standard attributes.

Also removes the @ts-expect-error JSX props since the attributes are
now set imperatively via the ref callback.

CHANGELOG.md

@@ -28,6 +28,7 @@
 - Search/listing performance: cut embedding hydration and badge read bandwidth via `embeddingSkillMap` + denormalized skill badges; shift stat-doc sync to low-frequency cron (#441) (thanks @sethconvex).
 
 ### Fixed
+- Upload: keep folder-picking enabled after page refresh by reapplying `webkitdirectory`/`directory` on the file input ref (#551) (thanks @MunemHashmi).
 - Skills hard-delete: delete `commentReports` rows during moderation cleanup to avoid orphaned report records.
 - Comments: hide entries authored by deleted/deactivated users in `comments:listBySkill`.
 - Admin API: `POST /api/v1/users/reclaim` now performs non-destructive root-slug owner transfer

src/routes/upload.tsx

@@ -77,6 +77,13 @@ export function Upload() {
   const [error, setError] = useState<string | null>(null)
   const [isDragging, setIsDragging] = useState(false)
   const fileInputRef = useRef<HTMLInputElement | null>(null)
+  const setFileInputRef = (node: HTMLInputElement | null) => {
+    fileInputRef.current = node
+    if (node) {
+      node.setAttribute('webkitdirectory', '')
+      node.setAttribute('directory', '')
+    }
+  }
   const validationRef = useRef<HTMLDivElement | null>(null)
   const navigate = useNavigate()
   const maxBytes = 50 * 1024 * 1024
@@ -272,11 +279,8 @@ export function Upload() {
     slugCollision,
   ])
 
-  useEffect(() => {
-    if (!fileInputRef.current) return
-    fileInputRef.current.setAttribute('webkitdirectory', '')
-    fileInputRef.current.setAttribute('directory', '')
-  }, [])
+  // webkitdirectory/directory attributes are set via the ref callback (setFileInputRef)
+  // to ensure they persist across hydration and re-renders (#58)
 
   if (!isAuthenticated) {
     return (
@@ -448,15 +452,12 @@ export function Upload() {
             }}
           >
             <input
-              ref={fileInputRef}
+              ref={setFileInputRef}
               className="upload-file-input"
               id="upload-files"
               data-testid="upload-input"
               type="file"
               multiple
-              // @ts-expect-error - non-standard attribute to allow folder selection
-              webkitdirectory=""
-              directory=""
               onChange={(event) => {
                 const picked = Array.from(event.target.files ?? [])
                 void applyExpandedFiles(picked)