fix: keep a detached job's card unsettled in a mid-turn save

frontend/src/lib/components/copilot/chat/AIChatManager.svelte.ts

@@ -4597,10 +4597,15 @@ export class AIChatManager {
 	// through here first.
 	private settledToolDisplay = (
 		messages: DisplayMessage[],
-		messageText: string
+		messageText: string,
+		shouldSettle: (message: ToolDisplayMessage) => boolean = () => true
 	): DisplayMessage[] =>
 		messages.map((message) => {
-			if (message.role === 'tool' && (message.isLoading || message.isQueued)) {
+			if (
+				message.role === 'tool' &&
+				(message.isLoading || message.isQueued) &&
+				shouldSettle(message)
+			) {
 				// Stopping the turn does not stop the job, and between Run and the job's id
 				// there is no way to know whether the server queued one: nothing threads the
 				// abort into that request, so it lands either way. That window says so
@@ -4652,9 +4657,19 @@ export class AIChatManager {
 	/** What the transcript would be if the turn stopped here — for the writes that fire
 	 * mid-turn without ending it. Loading is a property of this page: reloading resolves
 	 * no card, so one stored still pending comes back asking for input nothing can
-	 * deliver. Settles the stored copy only; the live turn keeps its cards. */
-	#interruptedSnapshot = (): DisplayMessage[] =>
-		this.settledToolDisplay(this.displayMessages, 'Interrupted')
+	 * deliver. Settles the stored copy only; the live turn keeps its cards.
+	 *
+	 * Except a detached job's card, which the poller does resolve after a reload: settling
+	 * that one stores an "Interrupted" error, and the patch a completed job merges in
+	 * carries no error to clear it with. */
+	#interruptedSnapshot = (): DisplayMessage[] => {
+		const detached = new Set(this.backgroundJobs.filter((j) => j.detached).map((j) => j.toolCallId))
+		return this.settledToolDisplay(
+			this.displayMessages,
+			'Interrupted',
+			(message) => !detached.has(message.tool_call_id)
+		)
+	}
 }
 
 export const aiChatManager = new AIChatManager()

frontend/src/lib/components/copilot/chat/AIChatManager.test.ts

@@ -3872,6 +3872,22 @@ describe('AIChatManager background job completion', () => {
 		expect(manager.pendingJobNotes[0]).toContain('"rowCount": 2')
 	})
 
+	// Detaching persists while the card is still loading. Storing it as interrupted would
+	// stick, because the patch a completed job merges in carries no error to clear.
+	it("stores a detached job's card unsettled, so a later success is not left an error", async () => {
+		const manager = new AIChatManager()
+		manager.registerJob(datatableJob)
+		manager.applyToolStatus('tc-1', { content: 'running in background', isLoading: true })
+		const saveChat = vi.spyOn(manager.historyManager, 'saveChat').mockResolvedValue(undefined)
+
+		manager.markJobDetached('job-1')
+		await vi.waitFor(() => expect(saveChat).toHaveBeenCalled())
+
+		const stored = (saveChat.mock.calls.at(-1)?.[0] as any[]).find((m) => m.tool_call_id === 'tc-1')
+		expect(stored.error).toBeUndefined()
+		expect(stored.content).toBe('running in background')
+	})
+
 	it('skips reconstruction and emits no note for a canceled detached job', async () => {
 		const manager = new AIChatManager()
 		manager.registerJob(datatableJob)