Add /answer endpoint for rich prompt responses

Adds new POST /api/prompts/:id/answer endpoint that handles AnswerResponse types:
- option: sends value + newline to PTY
- text: sends user input + newline to PTY
- tab_instructions: placeholder implementation sends selected_option (TODO: needs key sequences)

Updated /approve and /reject endpoints to use "1\n" and "3\n" instead of "y\n" and "n\n"
for consistency with option-based responses. Marked as legacy endpoints for backward compatibility.

src/server.ts

@@ -14,7 +14,12 @@ import {
   respondToPrompt,
   updateLastSeen,
 } from "./db";
-import type { ClientMessage, ServerMessage, SSEEvent } from "./types";
+import type {
+  AnswerResponse,
+  ClientMessage,
+  ServerMessage,
+  SSEEvent,
+} from "./types";
 
 // Server state
 const sseClients = new Set<ReadableStreamDefaultController<string>>();
@@ -133,6 +138,67 @@ const server = Bun.serve<SessionData>({
         return new Response("Invalid prompt ID", { status: 400 });
       }
 
+      // New unified answer endpoint
+      if (url.pathname.endsWith("/answer") && req.method === "POST") {
+        const prompt = getPrompt(promptId);
+        if (!prompt) {
+          return new Response("Prompt not found", { status: 404 });
+        }
+        if (prompt.response !== null) {
+          return new Response("Prompt already responded", { status: 400 });
+        }
+
+        const body = (await req.json()) as { response?: unknown };
+        if (!body.response || typeof body.response !== "object") {
+          return new Response("Missing or invalid response", { status: 400 });
+        }
+
+        const answer = body.response as AnswerResponse;
+        let inputData: string;
+
+        // Handle each response type
+        if (answer.type === "option") {
+          inputData = `${answer.value}\n`;
+        } else if (answer.type === "text") {
+          inputData = `${answer.value}\n`;
+        } else if (answer.type === "tab_instructions") {
+          // TODO: Implement proper key sequence handling for tab instructions
+          // For now, just send the selected option number
+          inputData = `${answer.selected_option}\n`;
+          console.debug(
+            `TODO: tab_instructions needs key sequence implementation - instruction: "${answer.instruction}"`,
+          );
+        } else {
+          return new Response("Invalid response type", { status: 400 });
+        }
+
+        // Mark as responded in DB
+        respondToPrompt(
+          promptId,
+          answer.type === "option" ? answer.value : "custom",
+        );
+
+        // Notify CLI via WebSocket
+        const ws = sessionWebSockets.get(prompt.session_id);
+        if (ws) {
+          const message: ServerMessage = { type: "input", data: inputData };
+          ws.send(JSON.stringify(message));
+        }
+
+        // Broadcast to dashboards
+        broadcastSSE({
+          type: "prompt_response",
+          prompt_id: promptId,
+          response:
+            answer.type === "option" && answer.value === "1"
+              ? "approve"
+              : "reject",
+        });
+
+        return Response.json({ success: true });
+      }
+
+      // Legacy approve endpoint (backward compatibility)
       if (url.pathname.endsWith("/approve") && req.method === "POST") {
         const prompt = getPrompt(promptId);
         if (!prompt) {
@@ -144,10 +210,10 @@ const server = Bun.serve<SessionData>({
 
         respondToPrompt(promptId, "approve");
 
-        // Notify CLI via WebSocket
+        // Notify CLI via WebSocket (using "1\n" for option 1)
         const ws = sessionWebSockets.get(prompt.session_id);
         if (ws) {
-          const message: ServerMessage = { type: "input", data: "y\n" };
+          const message: ServerMessage = { type: "input", data: "1\n" };
           ws.send(JSON.stringify(message));
         }
 
@@ -161,6 +227,7 @@ const server = Bun.serve<SessionData>({
         return Response.json({ success: true });
       }
 
+      // Legacy reject endpoint (backward compatibility)
       if (url.pathname.endsWith("/reject") && req.method === "POST") {
         const prompt = getPrompt(promptId);
         if (!prompt) {
@@ -172,10 +239,10 @@ const server = Bun.serve<SessionData>({
 
         respondToPrompt(promptId, "reject");
 
-        // Notify CLI via WebSocket
+        // Notify CLI via WebSocket (using "3\n" for option 3)
         const ws = sessionWebSockets.get(prompt.session_id);
         if (ws) {
-          const message: ServerMessage = { type: "input", data: "n\n" };
+          const message: ServerMessage = { type: "input", data: "3\n" };
           ws.send(JSON.stringify(message));
         }