Method wireWsEvents

src/server/web/session-manager.ts:273–316

* Wire WebSocket → PTY (input, resize, ping). * On close/error, start the grace period instead of immediately destroying * the session — this keeps the PTY alive for reconnection. * Called once per WebSocket connection (safe to call again on reconnect).

(token: string, ws: WebSocket, pty: IPty)

   * Called once per WebSocket connection (safe to call again on reconnect).
   */
  private wireWsEvents(token: string, ws: WebSocket, pty: IPty): void {
    ws.on("message", (data: Buffer | string) => {
      const str = data.toString();
      if (str.startsWith("{")) {
        try {
          const msg = JSON.parse(str) as Record<string, unknown>;
          if (
            msg.type === "resize" &&
            typeof msg.cols === "number" &&
            typeof msg.rows === "number"
          ) {
            pty.resize(msg.cols as number, msg.rows as number);
            return;
          }
          if (msg.type === "ping") {
            if (ws.readyState === 1 /* OPEN */) {
              ws.send(JSON.stringify({ type: "pong" }));
            }
            return;
          }
        } catch {
          // Not JSON — treat as terminal input
        }
      }
      pty.write(str);
    });

    const handleClose = () => {
      console.log(`[session ${token.slice(0, 8)}] WebSocket closed`);
      const session = this.store.get(token);
      // Only start grace if this WS is still the one attached to the session
      if (session && session.ws === ws) {
        this.store.startGrace(token, () => {
          /* logged inside startGrace */
        });
      }
    };

    ws.on("close", handleClose);
    ws.on("error", (err) => {
      console.error(`[session ${token.slice(0, 8)}] WebSocket error:`, err.message);
      handleClose();
    });
  }

  /**
   * Force-kill a session immediately (used by the REST API).