feat: Add environment variables to external team_authz commands

[david-lawrence-tc]

what

Adds additional environment variables to external authz commands:

• WORKSPACE - The Terraform workspace used for the project, ex. default
• API - "true" if invoked by API endpoints
• VERBOSE - "true" when the user would like verbose output

why

• It is common to map terraform workspaces to environments (for example dev, stage, prod)
• This allows an external authz script to allow/deny commands based on workspace name
• For example to allow broader access for lower environments, but keep prod workspaces more restricted
• This is not currently possible to do with external authz because the WORKSPACE env var is not passed to this command

tests

• Added unit tests
• Deployed this version to my environment and verified the new environments variables are passed to the script without errors

references

closes #6342

[Copilot]

Pull request overview

Adds additional context to external team allowlist/authz command executions by exporting more information via environment variables.

Changes:

• Pass WORKSPACE, API, and VERBOSE env vars to external team allowlist commands.
• Add unit tests covering the new env vars (plus some existing env behaviors).
• Document the newly supported env vars in the permissions docs.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
server/core/runtime/external_team_allowlist_runner.go	Exports WORKSPACE, API, and VERBOSE in the runner’s environment.
server/core/runtime/external_team_allowlist_runner_test.go	Adds test coverage for env propagation and runner behavior.
runatlantis.io/docs/repo-and-project-permissions.md	Documents the additional env vars available to external commands.