feat(sdk): add environment and secret management

[justusschock]

Summary

• add generic user and teamspace secret list/set/delete support in Python and Go
• add Studio environment variable management in Python and Go, plus Deployment environment variable management in Python
• add resource-first CLI commands with redacted JSON listings and safe secret input
• isolate Teamspace tests from persisted user configuration

Why

Configuration management should follow backend-supported resource scopes without exposing secret values or conflating generic and typed secrets.

Commands

User secrets

lightning user secret list [--json]
lightning user secret set KEY [--value-stdin] [--json]
lightning user secret delete KEY [--json]

Without --value-stdin, set reads the secret from a hidden interactive prompt.

Teamspace secrets

lightning teamspace secret list [--teamspace OWNER/TEAMSPACE] [--json]
lightning teamspace secret set KEY [--teamspace OWNER/TEAMSPACE] [--value-stdin] [--json]
lightning teamspace secret delete KEY [--teamspace OWNER/TEAMSPACE] [--json]

--teamspace defaults to the current Teamspace. Without --value-stdin, set reads the secret from a hidden interactive prompt.

Studio environment variables

lightning studio env list [--name STUDIO] [--teamspace OWNER/TEAMSPACE] [--json]
lightning studio env set KEY=VALUE [--name STUDIO] [--teamspace OWNER/TEAMSPACE] [--json]
lightning studio env delete KEY [--name STUDIO] [--teamspace OWNER/TEAMSPACE] [--json]

--name falls back to the current Studio or configured default. --teamspace defaults to the current Teamspace.

Deployment environment variables

lightning deployment env list --name DEPLOYMENT [--teamspace OWNER/TEAMSPACE] [--json]
lightning deployment env set KEY=VALUE --name DEPLOYMENT [--teamspace OWNER/TEAMSPACE] [--json]
lightning deployment env delete KEY --name DEPLOYMENT [--teamspace OWNER/TEAMSPACE] [--json]

--name is required. --teamspace defaults to the current Teamspace.

User impact

Users can manage supported secrets and direct environment variables through SDK resources and the lightning CLI. Studio and organization secret stores remain out of scope because those APIs do not exist.