feat: auto-create ClientTimelineEntry via Prisma middleware

CalendarEvent and FeedCard now automatically get a ClientTimelineEntry
when created/updated with a contactId. This ensures events created by
the agent (or any other code path) appear in the contact timeline
without needing explicit upsertClientTimelineEntry calls.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/server/utils/prisma.ts

@@ -11,6 +11,44 @@ export const prisma =
     log: ["error", "warn"],
   });
 
+// ---------------------------------------------------------------------------
+// Auto-sync ClientTimelineEntry for CalendarEvent, WorkspaceDocument, FeedCard
+// ---------------------------------------------------------------------------
+const TIMELINE_MODEL_MAP: Record<string, string> = {
+  CalendarEvent: "CALENDAR_EVENT",
+  FeedCard: "RECOMMENDATION",
+};
+
+prisma.$use(async (params, next) => {
+  const result = await next(params);
+
+  const contentType = params.model ? TIMELINE_MODEL_MAP[params.model] : undefined;
+  if (!contentType) return result;
+  if (params.action !== "create" && params.action !== "update" && params.action !== "upsert") return result;
+  if (!result || typeof result !== "object") return result;
+
+  const row = result as Record<string, any>;
+  const teamId = row.teamId as string | undefined;
+  const contactId = row.contactId as string | undefined;
+  const id = row.id as string | undefined;
+  if (!teamId || !contactId || !id) return result;
+
+  const datetime = row.startsAt ?? row.happenedAt ?? row.createdAt ?? new Date();
+
+  prisma.clientTimelineEntry
+    .upsert({
+      where: {
+        teamId_contentType_contentId: { teamId, contentType, contentId: id },
+      },
+      create: { teamId, contactId, contentType, contentId: id, datetime },
+      update: { contactId, datetime },
+      select: { id: true },
+    })
+    .catch(() => {});
+
+  return result;
+});
+
 if (process.env.NODE_ENV !== "production") {
   globalThis.__prisma = prisma;
 }