Redesign login UI, add theme toggle, refactor user update

- Redesigned login page with two-panel layout and branding
- Added HexaDistro logo and theme toggle to sidebar/header
- Refactored user update: roles via update endpoint, removed assignRole API/controller
- Extended UpdateUserRequest for username, role, password changes
- UserService.UpdateAsync syncs changes with AuthHex, with rollback
- Stock balances client dedupes by itemId-locationId
- Middleware matcher excludes static assets from auth checks
- Improved localStorage clearing for user context
- Added lucide-react for icons
- Minor UI/code cleanups for consistency and UX

distribution_fe/app/(dashboard)/users/_components/user-sheet.tsx

@@ -83,10 +83,10 @@ export function UserSheet({ open, onClose, user, roles, users, onSuccess }: User
 
   async function onEditSubmit(values: EditValues) {
     try {
-      await usersApi.update(user!.id, { fullName: values.fullName })
-      if (values.roleId !== user!.roleId) {
-        await usersApi.assignRole(user!.id, values.roleId)
-      }
+      await usersApi.update(user!.id, {
+        fullName: values.fullName,
+        roleId: values.roleId !== user!.roleId ? values.roleId : undefined,
+      })
       toast.add({ title: 'User updated', type: 'success' })
       onSuccess()
       onClose()