fix(site/src/pages/AgentsPage): clear retry banner on stream forward progress (#23653)

When a provider request fails and retries, the "Retrying request" banner
lingered in the UI after the retry succeeded. This happened because
`retryState` was only cleared on explicit `status` events (`running`,
`pending`, `waiting`), not when the stream resumed with `message_part`
or `message` events. Since the backend does not publish a
dedicated"retry resolved" event, the banner stayed visible for the
entire duration of the successful response.

Add `store.clearRetryState()` calls to the `message_part`, `message`,
and `status` event handlers so the banner disappears as soon as content
flows again.

Closes https://github.com/coder/coder/issues/23624

site/src/pages/AgentsPage/components/AgentDetail/ChatContext.test.tsx

@@ -1828,6 +1828,92 @@ describe("useChatStore", () => {
 		expect(result.current.retryState).toBeNull();
 	});
 
+	it("clears retryState when message_part arrives after retry", async () => {
+		immediateAnimationFrame();
+
+		const chatID = "chat-retry-message-part";
+		const mockSocket = createMockSocket();
+		mockWatchChatReturn(mockSocket);
+
+		const queryClient = createTestQueryClient();
+		const wrapper = ({ children }: PropsWithChildren) => (
+			<QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+		);
+		const setChatErrorReason = vi.fn();
+		const clearChatErrorReason = vi.fn();
+
+		const { result } = renderHook(
+			() => {
+				const { store } = useChatStore({
+					chatID,
+					chatMessages: [],
+					chatRecord: makeChat(chatID),
+					chatMessagesData: {
+						messages: [],
+						queued_messages: [],
+						has_more: false,
+					},
+					chatQueuedMessages: [],
+					setChatErrorReason,
+					clearChatErrorReason,
+				});
+				return {
+					retryState: useChatSelector(store, selectRetryState),
+					streamState: useChatSelector(store, selectStreamState),
+				};
+			},
+			{ wrapper },
+		);
+
+		await waitFor(() => {
+			expect(watchChat).toHaveBeenCalledWith(chatID, undefined);
+		});
+
+		act(() => {
+			mockSocket.emitData({
+				type: "retry",
+				chat_id: chatID,
+				retry: {
+					attempt: 1,
+					error: "rate limited",
+					kind: "rate_limit",
+					provider: "anthropic",
+					delay_ms: 3000,
+					retrying_at: "2025-01-01T00:00:30.000Z",
+				},
+			});
+		});
+
+		await waitFor(() => {
+			expect(result.current.retryState).toEqual({
+				attempt: 1,
+				error: "rate limited",
+				kind: "rate_limit",
+				provider: "anthropic",
+				delayMs: 3000,
+				retryingAt: "2025-01-01T00:00:30.000Z",
+			});
+		});
+
+		act(() => {
+			mockSocket.emitData({
+				type: "message_part",
+				chat_id: chatID,
+				message_part: {
+					role: "assistant",
+					part: { type: "text", text: "retry recovered" },
+				},
+			});
+		});
+
+		await waitFor(() => {
+			expect(result.current.retryState).toBeNull();
+			expect(result.current.streamState?.blocks).toEqual([
+				{ type: "response", text: "retry recovered" },
+			]);
+		});
+	});
+
 	it("routes status events for other chatIDs to subagent overrides", async () => {
 		immediateAnimationFrame();
 

site/src/pages/AgentsPage/components/AgentDetail/ChatContext.ts

@@ -946,6 +946,7 @@ export const useChatStore = (
 						}
 						const part = streamEvent.message_part?.part;
 						if (part) {
+							store.clearRetryState();
 							cancelScheduledStreamReset();
 							partsBuf.push(part);
 						}
@@ -962,6 +963,7 @@ export const useChatStore = (
 							if (streamEvent.chat_id && streamEvent.chat_id !== chatID) {
 								continue;
 							}
+							store.clearRetryState();
 							pendingMessages.push(message);
 							if (
 								message.id !== undefined &&
@@ -997,6 +999,7 @@ export const useChatStore = (
 								continue;
 							}
 
+							store.clearRetryState();
 							store.setChatStatus(nextStatus);
 							if (nextStatus === "pending" || nextStatus === "waiting") {
 								store.clearStreamState();