Add SSH TOTP authentication support (#350)

* Add SSH TOTP authentication support

- Implement keyboard-interactive authentication for SSH connections
- Add TOTP dialog component for Terminal and File Manager
- Handle TOTP prompts in WebSocket and HTTP connections
- Disable Server Stats for TOTP-enabled servers
- Add i18n support for TOTP-related messages

* Update src/backend/ssh/server-stats.ts

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Update src/backend/ssh/file-manager.ts

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

---------

Co-authored-by: ZacharyZcR <zacharyzcr1984@gmail.com>
Co-authored-by: Karmaa <88517757+LukeGus@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

src/backend/ssh/terminal.ts

@@ -154,6 +154,7 @@ wss.on("connection", async (ws: WebSocket, req) => {
   let sshConn: Client | null = null;
   let sshStream: ClientChannel | null = null;
   let pingInterval: NodeJS.Timeout | null = null;
+  let keyboardInteractiveFinish: ((responses: string[]) => void) | null = null;
 
   ws.on("close", () => {
     const userWs = userConnections.get(userId);
@@ -257,6 +258,33 @@ wss.on("connection", async (ws: WebSocket, req) => {
         ws.send(JSON.stringify({ type: "pong" }));
         break;
 
+      case "totp_response":
+        if (keyboardInteractiveFinish && data?.code) {
+          const totpCode = data.code;
+          sshLogger.info("TOTP code received from user", {
+            operation: "totp_response",
+            userId,
+            codeLength: totpCode.length,
+          });
+
+          keyboardInteractiveFinish([totpCode]);
+          keyboardInteractiveFinish = null;
+        } else {
+          sshLogger.warn("TOTP response received but no callback available", {
+            operation: "totp_response_error",
+            userId,
+            hasCallback: !!keyboardInteractiveFinish,
+            hasCode: !!data?.code,
+          });
+          ws.send(
+            JSON.stringify({
+              type: "error",
+              message: "TOTP authentication state lost. Please reconnect.",
+            }),
+          );
+        }
+        break;
+
       default:
         sshLogger.warn("Unknown message type received", {
           operation: "websocket_message_unknown_type",
@@ -557,10 +585,56 @@ wss.on("connection", async (ws: WebSocket, req) => {
       cleanupSSH(connectionTimeout);
     });
 
+    sshConn.on(
+      "keyboard-interactive",
+      (
+        name: string,
+        instructions: string,
+        instructionsLang: string,
+        prompts: Array<{ prompt: string; echo: boolean }>,
+        finish: (responses: string[]) => void,
+      ) => {
+        sshLogger.info("Keyboard-interactive authentication requested", {
+          operation: "ssh_keyboard_interactive",
+          hostId: id,
+          promptsCount: prompts.length,
+          instructions: instructions || "none",
+        });
+
+        const totpPrompt = prompts.find((p) =>
+          /verification code|verification_code|token|otp|2fa|authenticator|google.*auth/i.test(
+            p.prompt,
+          ),
+        );
+
+        if (totpPrompt) {
+          keyboardInteractiveFinish = finish;
+          ws.send(
+            JSON.stringify({
+              type: "totp_required",
+              prompt: totpPrompt.prompt,
+            }),
+          );
+        } else {
+          if (resolvedCredentials.password) {
+            const responses = prompts.map(() => resolvedCredentials.password || "");
+            finish(responses);
+          } else {
+            sshLogger.warn("Keyboard-interactive requires password but none available", {
+              operation: "ssh_keyboard_interactive_no_password",
+              hostId: id,
+            });
+            finish(prompts.map(() => ""));
+          }
+        }
+      },
+    );
+
     const connectConfig: any = {
       host: ip,
       port,
       username,
+      tryKeyboard: true,
       keepaliveInterval: 30000,
       keepaliveCountMax: 3,
       readyTimeout: 60000,