fix: render insights with nullable calendar data

src/lib/components/AIInsightPanel.svelte

@@ -236,13 +236,13 @@
             <p class="text-muted-foreground mt-2 text-sm leading-7">{insight.copy.future90Days.body}</p>
           </article>
         {/if}
-        {#if insight.calendarContext.length}
+        {#if insight.calendarContext?.length}
           <div>
             <h3 class="flex items-center gap-2 text-sm font-bold">
               <CalendarDaysIcon class="size-4" /> رویدادهای مرتبط
             </h3>
             <div class="mt-3 flex flex-wrap gap-2">
-              {#each insight.calendarContext as event}<span
+              {#each insight.calendarContext ?? [] as event}<span
                   class={`rounded-md border px-3 py-2 text-xs ${eventTone(event.tone)}`}
                   >{event.titleFa} · {formatDate(event.startDate)}</span
                 >{/each}

src/lib/components/AIInsightPanel.test.ts

@@ -51,7 +51,7 @@ const insight: AIInsight = {
     options: [],
   },
   evidence: {},
-  calendarContext: [],
+  calendarContext: null as unknown as AIInsight['calendarContext'],
   refreshState: { state: 'IDLE' },
   sectionRefreshState: {},
   generatedAt: '2026-08-22T00:00:00Z',