fix: preserve subagent thread routing (#1241)

Thanks @gnarco.

Co-authored-by: gnarco <gnarco@users.noreply.github.com>

src/config/sessions/store.ts

@@ -56,11 +56,13 @@ function normalizeSessionEntryDelivery(entry: SessionEntry): SessionEntry {
   const sameDelivery =
     (entry.deliveryContext?.channel ?? undefined) === nextDelivery?.channel &&
     (entry.deliveryContext?.to ?? undefined) === nextDelivery?.to &&
-    (entry.deliveryContext?.accountId ?? undefined) === nextDelivery?.accountId;
+    (entry.deliveryContext?.accountId ?? undefined) === nextDelivery?.accountId &&
+    (entry.deliveryContext?.threadId ?? undefined) === nextDelivery?.threadId;
   const sameLast =
     entry.lastChannel === normalized.lastChannel &&
     entry.lastTo === normalized.lastTo &&
-    entry.lastAccountId === normalized.lastAccountId;
+    entry.lastAccountId === normalized.lastAccountId &&
+    entry.lastThreadId === normalized.lastThreadId;
   if (sameDelivery && sameLast) return entry;
   return {
     ...entry,
@@ -68,6 +70,7 @@ function normalizeSessionEntryDelivery(entry: SessionEntry): SessionEntry {
     lastChannel: normalized.lastChannel,
     lastTo: normalized.lastTo,
     lastAccountId: normalized.lastAccountId,
+    lastThreadId: normalized.lastThreadId,
   };
 }
 
@@ -379,11 +382,12 @@ export async function updateLastRoute(params: {
   channel?: SessionEntry["lastChannel"];
   to?: string;
   accountId?: string;
+  threadId?: string | number;
   deliveryContext?: DeliveryContext;
   ctx?: MsgContext;
   groupResolution?: import("./types.js").GroupKeyResolution | null;
 }) {
-  const { storePath, sessionKey, channel, to, accountId, ctx } = params;
+  const { storePath, sessionKey, channel, to, accountId, threadId, ctx } = params;
   return await withSessionStoreLock(storePath, async () => {
     const store = loadSessionStore(storePath);
     const existing = store[sessionKey];
@@ -393,6 +397,7 @@ export async function updateLastRoute(params: {
       channel,
       to,
       accountId,
+      threadId,
     });
     const mergedInput = mergeDeliveryContext(explicitContext, inlineContext);
     const merged = mergeDeliveryContext(mergedInput, deliveryContextFromSession(existing));
@@ -401,6 +406,7 @@ export async function updateLastRoute(params: {
         channel: merged?.channel,
         to: merged?.to,
         accountId: merged?.accountId,
+        threadId: merged?.threadId,
       },
     });
     const metaPatch = ctx
@@ -417,6 +423,7 @@ export async function updateLastRoute(params: {
       lastChannel: normalized.lastChannel,
       lastTo: normalized.lastTo,
       lastAccountId: normalized.lastAccountId,
+      lastThreadId: normalized.lastThreadId,
     };
     const next = mergeSessionEntry(
       existing,

src/config/sessions/types.ts

@@ -89,6 +89,7 @@ export type SessionEntry = {
   lastChannel?: SessionChannelId;
   lastTo?: string;
   lastAccountId?: string;
+  lastThreadId?: string | number;
   skillsSnapshot?: SessionSkillSnapshot;
   systemPromptReport?: SessionSystemPromptReport;
 };