Method spawn

src/node/services/backgroundProcessManager.ts:598–702

* Spawn a new process with background-style infrastructure. * * All processes are spawned with nohup/setsid and file-based output, * enabling seamless fg→bg transition via sendToBackground(). * * @param runtime Runtime to spawn the process on * @param workspaceId Workspace ID for t

(
    runtime: Runtime,
    workspaceId: string,
    script: string,
    config: {
      cwd: string;
      env?: Record<string, string>;
      /** Human-readable name for the process - used to generate the process ID */
      displayName: string;
      /** If true, process is foreground (being waited on). Default: false (background) */
      isForeground?: boolean;
      /** Optional write-time monitor for background output. */
      monitor?: BackgroundProcessMonitorConfig;
      /** Auto-terminate after this many seconds (background processes only) */
      timeoutSecs?: number;
    }
  )

   * @param config Execution configuration
   */
  async spawn(
    runtime: Runtime,
    workspaceId: string,
    script: string,
    config: {
      cwd: string;
      env?: Record<string, string>;
      /** Human-readable name for the process - used to generate the process ID */
      displayName: string;
      /** If true, process is foreground (being waited on). Default: false (background) */
      isForeground?: boolean;
      /** Optional write-time monitor for background output. */
      monitor?: BackgroundProcessMonitorConfig;
      /** Auto-terminate after this many seconds (background processes only) */
      timeoutSecs?: number;
    }
  ): Promise<
    | { success: true; processId: string; outputDir: string; pid: number }
    | { success: false; error: string }
  > {
    log.debug(`BackgroundProcessManager.spawn() called for workspace ${workspaceId}`);

    const processId = this.generateUniqueProcessId(config.displayName);

    // Spawn via executor with background infrastructure
    // spawnProcess uses runtime.tempDir() internally for output directory
    const result = await spawnProcess(runtime, script, {
      cwd: config.cwd,
      workspaceId,
      processId,
      env: config.env,
    });

    if (!result.success) {
      log.debug(`BackgroundProcessManager: Failed to spawn: ${result.error}`);
      return { success: false, error: result.error };
    }

    const { handle, pid, outputDir } = result;
    const startTime = Date.now();

    // Write meta.json with process info
    const meta: BackgroundProcessMeta = {
      id: processId,
      pid,
      script,
      startTime,
      status: "running",
      displayName: config.displayName,
    };
    await handle.writeMeta(JSON.stringify(meta, null, 2));

    const proc: BackgroundProcess = {
      id: processId,
      pid,
      workspaceId,
      outputDir,
      script,