v2.3.2-coder-answer-endpoint: fix ask_user_input submit in CoderPane

The CoderPane runs its own inference runner and broker on the boocoder
service. The AskUserInputCard was calling /api/chats/:id/answer_user_input
on the main BooChat server, which has a different inference runner — the
answer was accepted but the next turn was enqueued on the wrong runner,
so nothing happened.

Fix: register the same answer_user_input endpoint on the boocoder, and
add an apiPrefix prop to AskUserInputCard so the CoderPane routes
through /api/coder/chats/:id/answer_user_input. BooChat's MessageList
continues to use the default (no prefix) path.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/components/AskUserInputCard.tsx

@@ -1,7 +1,6 @@
 import { useMemo, useState } from 'react';
 import { Check } from 'lucide-react';
 import { toast } from 'sonner';
-import { api } from '@/api/client';
 import { RadioGroup, RadioGroupItem } from '@/components/ui/radio-group';
 import { Button } from '@/components/ui/button';
 import type {
@@ -22,6 +21,7 @@ interface Props {
   toolCall: ToolCall;
   toolResult: ToolResult | null;
   chatId: string;
+  apiPrefix?: string;
 }
 
 function parseQuestions(raw: unknown): AskUserQuestion[] {
@@ -63,7 +63,7 @@ function parseAnswerSet(raw: unknown): AskUserAnswerSet | null {
   return { answers };
 }
 
-export function AskUserInputCard({ toolCall, toolResult, chatId }: Props) {
+export function AskUserInputCard({ toolCall, toolResult, chatId, apiPrefix = '' }: Props) {
   const questions = useMemo(() => parseQuestions(toolCall.args), [toolCall.args]);
 
   if (questions.length === 0) {
@@ -74,9 +74,6 @@ export function AskUserInputCard({ toolCall, toolResult, chatId }: Props) {
     );
   }
 
-  // Tool result with a non-null output means the answer is already submitted.
-  // The pending sentinel uses output=null, so this branch only triggers after
-  // the real WS tool_result frame lands.
   const answered = toolResult && toolResult.output !== null;
   if (answered) {
     const answerSet = parseAnswerSet(toolResult!.output);
@@ -84,7 +81,7 @@ export function AskUserInputCard({ toolCall, toolResult, chatId }: Props) {
   }
 
   return (
-    <PendingView questions={questions} toolCallId={toolCall.id} chatId={chatId} />
+    <PendingView questions={questions} toolCallId={toolCall.id} chatId={chatId} apiPrefix={apiPrefix} />
   );
 }
 
@@ -92,10 +89,12 @@ function PendingView({
   questions,
   toolCallId,
   chatId,
+  apiPrefix = '',
 }: {
   questions: AskUserQuestion[];
   toolCallId: string;
   chatId: string;
+  apiPrefix?: string;
 }) {
   // Per-question selections + free text. Selections are option arrays so the
   // multi_select case is uniform; single_select just constrains to length 1.
@@ -133,9 +132,16 @@ function PendingView({
     if (submitting) return;
     setSubmitting(true);
     try {
-      await api.chats.answerUserInput(chatId, toolCallId, answers);
-      // Card stays mounted; the incoming WS tool_result frame will flip it
-      // into AnsweredView via the parent prop change.
+      const url = `${apiPrefix}/api/chats/${chatId}/answer_user_input`;
+      const res = await fetch(url, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ tool_call_id: toolCallId, answers }),
+      });
+      if (!res.ok) {
+        const body = await res.json().catch(() => ({})) as { error?: string; detail?: string };
+        throw new Error(body.detail ?? body.error ?? `HTTP ${res.status}`);
+      }
     } catch (err) {
       toast.error(err instanceof Error ? err.message : 'submit failed');
       setSubmitting(false);

apps/web/src/components/panes/CoderMessageList.tsx

@@ -230,6 +230,7 @@ export function CoderMessageList({ messages, chatId, footer }: Props) {
                   toolCall={item.run.call}
                   toolResult={item.run.result}
                   chatId={chatId}
+                  apiPrefix="/api/coder"
                 />
               );
             }