fix(mothership): say why a workflow copilot chat cannot read other chats

apps/sim/lib/mothership/chat/application/read-recall-chats.test.ts

@@ -196,11 +196,15 @@ describe("a chat's other chats", () => {
       readRecallChats.execute({ principal: organizationPrincipal(), input })
     ).rejects.toMatchObject({ code: 'forbidden' })
     resetDbChainMock()
-    // A workflow's copilot chat is no home chat, so it reads no home chats back.
+    // A workflow's copilot chat is no home chat, so it reads no home chats back, and says so
+    // rather than reporting its own chat missing.
     queueWorkspaceChat('agent', 'copilot')
     await expect(
       readRecallChats.execute({ principal: workspacePrincipal(), input })
-    ).rejects.toMatchObject({ code: 'not_found' })
+    ).rejects.toMatchObject({
+      code: 'forbidden',
+      message: "Reading other chats is available in home chats, not in a workflow's copilot chat",
+    })
     resetDbChainMock()
     queueOrganizationChat()
     authBanMockFns.mockGetActivelyBannedUserIds.mockResolvedValue(['actor'])

apps/sim/lib/mothership/chat/application/read-recall-chats.ts

@@ -100,7 +100,12 @@ export const readRecallChats = defineAuthorizedChatUseCase({
     },
   },
   async execute({ principal, context, input }): Promise<RecallChatsResponse> {
-    if (context.type !== 'mothership') throw new OrchestrationError('not_found', 'Chat not found')
+    if (context.type !== 'mothership') {
+      throw new OrchestrationError(
+        'forbidden',
+        "Reading other chats is available in home chats, not in a workflow's copilot chat"
+      )
+    }
     if (context.mode !== 'agent' && context.mode !== 'plan') {
       throw new OrchestrationError('forbidden', 'Reading other chats requires an agent chat')
     }