fix(mothership): keep the ended-run message surface-neutral and below a replay refusal

The fallback is shared by Chat, workflow execute and inbox, so it no longer
tells the reader to send a message. A replay refusal now wins by guard rather
than by spread order, with a test that covers the combination.

Author: waleedlatif1

apps/sim/lib/mothership/request/lifecycle/run.test.ts

@@ -2037,6 +2037,28 @@ describe('runCopilotLifecycle', () => {
     }
   )
 
+  it('reports a replay refusal over a reasonless error terminal', async () => {
+    const abortController = new AbortController()
+    const refusal = ownerRefusal()
+    mockRunStreamLoop.mockImplementationOnce(
+      async (_url: string, _init: RequestInit, context: StreamingContext): Promise<void> => {
+        context.completionStatus = MothershipStreamV1CompletionStatus.error
+        abortController.abort(refusal)
+      }
+    )
+
+    const result = await runWithStreamAbort(abortController)
+
+    expect(result).toEqual(
+      expect.objectContaining({
+        success: false,
+        cancelled: false,
+        error: refusal.userMessage,
+        errorCode: REPLAY_BUDGET_EXHAUSTED_CODE,
+      })
+    )
+  })
+
   it('keeps a Stop a cancellation when a replay refusal follows it', async () => {
     const abortController = new AbortController()
     mockRunStreamLoop.mockImplementationOnce(

apps/sim/lib/mothership/request/lifecycle/run.ts

@@ -90,9 +90,11 @@ const logger = createLogger('CopilotLifecycle')
 
 const COPILOT_MODEL_CONTENT_PROJECTION_ERROR = 'Copilot model input could not be safely projected'
 
-/** Shown when the worker ends a turn with an error terminal but gives no reason. */
-const ENDED_RUN_MESSAGE =
-  'This run had already ended before it could continue. Send a message to pick up where it left off.'
+/**
+ * Shown when the worker ends a turn with an error terminal but gives no reason. Every surface
+ * (Chat, workflow execute, inbox) reports it, so it carries no surface-specific next step.
+ */
+const ENDED_RUN_MESSAGE = 'This run had already ended before it could continue.'
 
 class CopilotModelContentProjectionError extends Error {
   constructor() {
@@ -577,11 +579,12 @@ export async function runCopilotLifecycle(
         !refusal &&
         !turnWasAborted &&
         (backendFinishedTurn || (!context.completionStatus && context.errors.length === 0))
-      // The worker sends an error terminal with no `error` event only when it rebuilds an
-      // ended run from its log, which drops the stored reason: a resume or reattach that
-      // reaches a run that already ended, for example at its deadline. Say so rather than
-      // leave the turn to a generic failure; a reported reason always wins.
+      // The worker sends an error terminal with no `error` event only when it replays a run
+      // that already ended (for example at its deadline) to a resume or reattach, because
+      // that replay does not carry the run's stored reason. Say so rather than leave the turn
+      // to a generic failure; a reported reason or a replay refusal always wins.
       const endedWithoutReason =
+        !refusal &&
         !turnWasAborted &&
         context.completionStatus === MothershipStreamV1CompletionStatus.error &&
         context.errors.length === 0