Method checkExistingContainer

src/node/runtime/DockerRuntime.ts:556–595

* Check if a container already exists and whether it's valid for reuse. * Returns action to take: skip setup, cleanup invalid container, or create new.

(
    containerName: string,
    workspacePath: string,
    branchName: string
  )

   * Returns action to take: skip setup, cleanup invalid container, or create new.
   */
  private async checkExistingContainer(
    containerName: string,
    workspacePath: string,
    branchName: string
  ): Promise<ContainerCheckResult> {
    const exists = await runDockerCommand(`docker inspect ${containerName}`, 10000);
    if (exists.exitCode !== 0) return { action: "create" };

    const isRunning = await runDockerCommand(
      `docker inspect -f '{{.State.Running}}' ${containerName}`,
      10000
    );
    if (isRunning.exitCode !== 0 || isRunning.stdout.trim() !== "true") {
      return { action: "cleanup", reason: "Removing stale container from previous attempt..." };
    }

    // Container running - validate it has an initialized git repo
    const gitCheck = await runDockerCommand(
      `docker exec ${containerName} test -d ${workspacePath}/.git`,
      5000
    );
    if (gitCheck.exitCode !== 0) {
      return {
        action: "cleanup",
        reason: "Container exists but repo not initialized, recreating...",
      };
    }

    // Verify correct branch is checked out
    // (handles edge case: crash after clone but before checkout left container on wrong branch)
    const branchCheck = await runDockerCommand(
      `docker exec ${containerName} git -C ${workspacePath} rev-parse --abbrev-ref HEAD`,
      5000
    );
    if (branchCheck.exitCode !== 0 || branchCheck.stdout.trim() !== branchName) {
      return { action: "cleanup", reason: "Container exists but wrong branch, recreating..." };
    }

    return { action: "skip" };
  }

  private async detectContainerUser(
    containerName: string,