Add dashboard management commands to the Lamdera CLI

[CharlonTank]

Summary

This PR adds a first set of dashboard-management commands to the Lamdera CLI:

• lamdera project add
• lamdera teams add
• lamdera ssh add
• lamdera env ls
• lamdera env add
• lamdera env update
• lamdera env rm

It also keeps lamdera env set as a direct upsert-style env update path.

What changed

• added a shared dashboard RPC client for project creation, team creation, SSH key upload, and env var fetch/save
• added CLI parsing and command wiring for the new dashboard commands
• added interactive fallbacks for project add and teams add when arguments are omitted
• added --scope support for project creation
• added --project support for env management, with --app kept as an alias
• updated env var parsing to allow names like API_KEY

Env behavior

The env command follows Lamdera's existing app-scoped env model.

• env vars are applied to the target Lamdera app
• preview and staging behavior continues to come from the existing deploy/app flow

Verification

• stack build elm:exe:lamdera --fast
• stack exec lamdera -- project --help
• stack exec lamdera -- teams --help
• stack exec lamdera -- ssh --help
• stack exec lamdera -- env --help