fix(client): send multiple_choice from the desktop poll form

client/src/components/Collab/CollabPolls.test.tsx

@@ -30,7 +30,7 @@ const buildPoll = (overrides: Record<string, unknown> = {}) => ({
     { id: 1, text: 'Paris', label: 'Paris', voters: [] },
     { id: 2, text: 'Rome', label: 'Rome', voters: [] },
   ],
-  multi_choice: false,
+  multiple_choice: false,
   is_closed: false,
   deadline: null,
   created_by: 1,

client/src/components/Collab/CollabPolls.tsx

@@ -26,7 +26,7 @@ interface Poll {
   id: number
   question: string
   options: PollOption[]
-  multi_choice: boolean
+  multiple_choice: boolean
   is_closed: boolean
   deadline: string | null
   created_by: number
@@ -59,7 +59,7 @@ function totalVotes(poll) {
 // ── Create Poll Modal ────────────────────────────────────────────────────────
 interface CreatePollModalProps {
   onClose: () => void
-  onCreate: (data: { question: string; options: string[]; multi_choice: boolean }) => Promise<void>
+  onCreate: (data: { question: string; options: string[]; multiple_choice: boolean }) => Promise<void>
   t: (key: string) => string
 }
 
@@ -80,7 +80,9 @@ function CreatePollModal({ onClose, onCreate, t }: CreatePollModalProps) {
     if (!canSubmit) return
     setSubmitting(true)
     try {
-      await onCreate({ question: question.trim(), options: options.filter(o => o.trim()), multi_choice: multiChoice })
+      // `multiple_choice` is the field the server reads (nest/collab/collab.service.ts);
+      // the old `multi_choice` name was silently dropped, losing desktop multi-choice.
+      await onCreate({ question: question.trim(), options: options.filter(o => o.trim()), multiple_choice: multiChoice })
       onClose()
     } catch {} finally { setSubmitting(false) }
   }
@@ -232,7 +234,7 @@ function PollCard({ poll, currentUser, canEdit, onVote, onClose, onDelete, t }:
                 <Clock size={8} /> {remaining}
               </span>
             )}
-            {poll.multi_choice && (
+            {poll.multiple_choice && (
               <span style={{ fontSize: 'calc(9px * var(--fs-scale-caption, 1))', fontWeight: 600, color: 'var(--text-faint)', background: 'var(--bg-tertiary)', padding: '2px 7px', borderRadius: 99 }}>
                 {t('collab.polls.multiChoice')}
               </span>

client/src/mobile/screens/trip/tabs/MCollabPolls.tsx

@@ -97,8 +97,8 @@ export default function MCollabPolls({ planner }: MCollabPollsProps) {
       const res = (await collabApi.createPoll(tripId, {
         question: data.question,
         options: data.options,
-        // Server reads `data.multiple || data.multiple_choice` (collabService.ts) —
-        // both are sent so either shape lands correctly.
+        // Server reads `data.multiple || data.multiple_choice`
+        // (nest/collab/collab.service.ts) — both are sent so either shape lands.
         multiple: data.multipleChoice,
         multiple_choice: data.multipleChoice,
         deadline: data.deadline || undefined,