feat(devcontainer): add optional name attribute to prevent sub-agent name collisions

[mmustafasenoglu]

Problem

When using for_each or count with coder_devcontainer, all instances share the same Terraform block name, causing sub-agent name collisions:

insert devcontainer "repos" subagent: insert subagent:
pq: workspace agent name "repos" already exists in this workspace build

Fix

Added an optional name attribute to the coder_devcontainer resource schema. When set, this name takes precedence over the Terraform block name when constructing the sub-agent name.

resource "coder_devcontainer" "repos" {
  for_each         = local.repos
  name             = each.value   # new attribute
  agent_id         = coder_agent.dev[0].id
  workspace_folder = "/home/user/workspaces/${each.value}"
  config_path      = "..."
}

Testing

Added TestDevcontainerWithName test case verifying the new attribute is properly stored.

Note: Server-side changes in coder/coder are also needed to read and use this name attribute when constructing the proto.Devcontainer.

Fixes #503

[github-actions]

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[mmustafasenoglu]

I have read the CLA Document and I hereby sign the CLA

[mmustafasenoglu]

recheck

[mmustafasenoglu]

Hi maintainers!

I've signed the CLA by commenting 'I have read the CLA Document and I hereby sign the CLA' but the CLA Assistant check is still failing. Could you please manually approve the CLA or re-trigger the CLA check?

The PR adds an optional attribute to to prevent sub-agent name collisions when using / (fixes #503).

Thanks!