feat(chat): add typed change-set summary message in timeline

Frontend/server/graphql/schema.ts

@@ -258,10 +258,12 @@ async function getChatMessages(auth: AuthContext | null) {
 
   return items.map((m) => {
     const cs = getChangeSetFromPlanJson(m.planJson);
+    const messageKind = getMessageKindFromPlanJson(m.planJson) ?? (cs ? "change_set_summary" : null);
     return {
       id: m.id,
       role: m.role === "USER" ? "user" : m.role === "ASSISTANT" ? "assistant" : "system",
       text: m.text,
+      messageKind,
       requestId: null,
       eventType: null,
       phase: null,
@@ -641,6 +643,27 @@ function getChangeSetFromPlanJson(planJson: unknown): ChangeSet | null {
   return cs as ChangeSet;
 }
 
+function getMessageKindFromPlanJson(planJson: unknown): string | null {
+  const debug = (planJson as any) ?? {};
+  const kind = debug?.messageKind;
+  if (!kind || typeof kind !== "string") return null;
+  return kind;
+}
+
+function renderChangeSetSummary(changeSet: ChangeSet): string {
+  const totals = { created: 0, updated: 0, deleted: 0 };
+  for (const item of changeSet.items) {
+    if (item.action === "created") totals.created += 1;
+    else if (item.action === "updated") totals.updated += 1;
+    else if (item.action === "deleted") totals.deleted += 1;
+  }
+
+  return [
+    "Technical change summary",
+    `Total: ${changeSet.items.length} · Created: ${totals.created} · Updated: ${totals.updated} · Archived: ${totals.deleted}`,
+  ].join("\n");
+}
+
 async function findLatestChangeCarrierMessage(auth: AuthContext | null) {
   const ctx = requireAuth(auth);
   const items = await prisma.chatMessage.findMany({
@@ -755,9 +778,24 @@ async function sendPilotMessage(auth: AuthContext | null, textInput: string) {
     eventType: "assistant",
     phase: "final",
     transient: false,
-    changeSet,
   });
 
+  if (changeSet) {
+    await persistChatMessage({
+      teamId: ctx.teamId,
+      conversationId: ctx.conversationId,
+      authorUserId: null,
+      role: "ASSISTANT",
+      text: renderChangeSetSummary(changeSet),
+      requestId,
+      eventType: "note",
+      phase: "final",
+      transient: false,
+      messageKind: "change_set_summary",
+      changeSet,
+    });
+  }
+
   return { ok: true };
 }
 
@@ -909,6 +947,7 @@ export const crmGraphqlSchema = buildSchema(`
     id: ID!
     role: String!
     text: String!
+    messageKind: String
     requestId: String
     eventType: String
     phase: String