refactor(routing): centralize inbound last-route policy

src/discord/monitor/route-resolution.test.ts

@@ -30,6 +30,7 @@ describe("discord route resolution helpers", () => {
       accountId: "default",
       sessionKey: "agent:main:discord:channel:c1",
       mainSessionKey: "agent:main:main",
+      lastRoutePolicy: "session",
       matchedBy: "default",
     };
 
@@ -54,6 +55,7 @@ describe("discord route resolution helpers", () => {
       accountId: "default",
       sessionKey: "agent:main:discord:channel:c1",
       mainSessionKey: "agent:main:main",
+      lastRoutePolicy: "session",
       matchedBy: "default",
     };
     const configuredRoute = {
@@ -62,6 +64,7 @@ describe("discord route resolution helpers", () => {
         agentId: "worker",
         sessionKey: "agent:worker:discord:channel:c1",
         mainSessionKey: "agent:worker:main",
+        lastRoutePolicy: "session" as const,
         matchedBy: "binding.peer" as const,
       },
     };

src/discord/monitor/route-resolution.ts

@@ -1,5 +1,6 @@
 import type { OpenClawConfig } from "../../config/config.js";
 import {
+  deriveLastRoutePolicy,
   resolveAgentRoute,
   type ResolvedAgentRoute,
   type RoutePeer,
@@ -90,6 +91,10 @@ export function resolveDiscordEffectiveRoute(params: {
     ...params.route,
     sessionKey: boundSessionKey,
     agentId: resolveAgentIdFromSessionKey(boundSessionKey),
+    lastRoutePolicy: deriveLastRoutePolicy({
+      sessionKey: boundSessionKey,
+      mainSessionKey: params.route.mainSessionKey,
+    }),
     ...(params.matchedBy ? { matchedBy: params.matchedBy } : {}),
   };
 }