Fix ticket timeline transcript typing and expansion.

Avoid nullable timeline entries by building a strict TimelineMessage array and keep storefront transcript splitting behavior stable for sorting and expansion controls.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/dashboard/juno-engine/tickets/[ticketId]/page.tsx

@@ -316,23 +316,31 @@ export default function TicketDetailPage() {
 
   const timelineMessages = useMemo<TimelineMessage[]>(() => {
     if (!ticket) return []
-    return ticket.messages.flatMap((message) => {
-      if (message.trigger !== "STOREFRONT_TICKET") return [{ ...message }]
+    const expanded: TimelineMessage[] = []
+    for (const message of ticket.messages) {
+      if (message.trigger !== "STOREFRONT_TICKET") {
+        expanded.push({ ...message })
+        continue
+      }
       const raw = cleanDisplayText(message.bodyPreview || "")
-      if (!raw) return [{ ...message }]
+      if (!raw) {
+        expanded.push({ ...message })
+        continue
+      }
       const lines = raw
         .split(/\r?\n/)
         .map((line) => line.trim())
         .filter(Boolean)
-      const parsed = lines
-        .map((line, idx) => {
+      const parsed: TimelineMessage[] = []
+      for (let idx = 0; idx < lines.length; idx += 1) {
+        const line = lines[idx]
         const match = line.match(/^\[(.+?)\]\s+(CUSTOMER|ASSISTANT):\s*(.+)$/i)
-          if (!match) return null
+        if (!match) continue
         const sentAtMaybe = new Date(match[1])
         const sentAt = Number.isNaN(sentAtMaybe.getTime())
           ? message.sentAt
           : sentAtMaybe.toISOString()
-          return {
+        parsed.push({
           id: `${message.id}-part-${idx}`,
           subject: message.subject,
           bodyPreview: match[3],
@@ -341,11 +349,15 @@ export default function TicketDetailPage() {
           sentAt,
           senderOverride:
             match[2].toUpperCase() === "CUSTOMER" ? ("CUSTOMER" as const) : ("ASSISTANT" as const),
-          } satisfies TimelineMessage
-        })
-        .filter((row): row is TimelineMessage => Boolean(row))
-      return parsed.length >= 2 ? parsed : [{ ...message }]
         })
+      }
+      if (parsed.length >= 2) {
+        expanded.push(...parsed)
+      } else {
+        expanded.push({ ...message })
+      }
+    }
+    return expanded
   }, [ticket])
 
   const sourceLabel = (trigger: string | null): string => {