Implement key sequence execution for tab instructions

Execute the tab instruction flow:
- Navigate to target option using arrow keys
- Send Tab to enter instruction mode
- Type the instruction text
- Send Enter to submit

The sequence runs asynchronously with proper delays between steps
(50ms between arrows, 100ms before Tab, 100ms before instruction).

src/server.ts

@@ -165,12 +165,68 @@ const server = Bun.serve<SessionData>({
         } 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: "${answer.instruction}"`,
+          // Execute key sequence for tab instructions with delays:
+          // 1. Navigate to selected_option (up/down arrows)
+          // 2. Wait 100ms
+          // 3. Send Tab key
+          // 4. Wait 100ms
+          // 5. Write instruction text
+          // 6. Send Enter key
+
+          const promptData = prompt.prompt_json;
+          if (!promptData || promptData.prompt_type !== "permission") {
+            return new Response("Tab instructions only valid for permission prompts", { status: 400 });
+          }
+
+          const currentOption = promptData.selected_option;
+          const targetOption = answer.selected_option;
+
+          // Mark as responded in DB first
+          respondToPrompt(
+            promptId,
+            `tab:${answer.selected_option}`,
           );
+
+          // Broadcast to dashboards
+          broadcastSSE({
+            type: "prompt_response",
+            prompt_id: promptId,
+            response: answer.selected_option === 1 ? "approve" : "reject",
+          });
+
+          // Get WebSocket for async execution
+          const ws = sessionWebSockets.get(prompt.session_id);
+          if (!ws) {
+            return new Response("Session WebSocket not found", { status: 404 });
+          }
+
+          // Execute key sequence asynchronously with delays
+          (async () => {
+            const sendInput = (data: string) => {
+              const message: ServerMessage = { type: "input", data };
+              ws.send(JSON.stringify(message));
+            };
+
+            // Navigate to target option
+            const diff = targetOption - currentOption;
+            const arrow = diff > 0 ? '\x1b[B' : '\x1b[A';
+            for (let i = 0; i < Math.abs(diff); i++) {
+              sendInput(arrow);
+              await Bun.sleep(50); // Small delay between arrows
+            }
+
+            await Bun.sleep(100);
+            sendInput('\t'); // Tab key
+
+            await Bun.sleep(100);
+            sendInput(answer.instruction); // Instruction text
+            sendInput('\n'); // Enter key
+          })().catch((err) => {
+            console.error("Error executing tab instruction sequence:", err);
+          });
+
+          // Return immediately (async execution continues in background)
+          return Response.json({ success: true });
         } else {
           return new Response("Invalid response type", { status: 400 });
         }