project.close() race condition

[gmaclennan]

Description

Non-urgent follow-up to #375.

With the currently implementation it's possible to hit a race condition while closing a project:

const closePromise = project.close() // Note: no await
const project = manager.getProject(projectId)
await closePromise()
await project.observation.getMany() // will fail because project is closed

Needs proper state management to fix: e.g. project.state: 'opening' | 'opened' | 'closing' | 'closed'. Then maybe rather than events based doing in getProject():

getProject(projectId) {
  const activeProject = this.#activeProjects.get(projectPublicId)
    if (activeProject && activeProject.state !== 'closed' && activeProject.state !== 'closing') return activeProject

This is fine to not address as a priority - we only close projects in tests. Just leaving this here in case we run into this issue in tests in the future.