Add structured env management with TOML config and justfile

[gyorgybalazsi]

Summary

• Replace comment/uncomment .env workflow with structured environments.toml config (per-environment + per-credential profiles)
• Add env.nu nushell script that generates .env by merging shared + environment + credential settings
• Add justfile with recipes for all examples, including auth-type guards that prevent running with wrong credential profile
• OWNER_FILTER removed from credential profiles — now passed as optional runtime arg to list-deposits-cc
• Add environments.example.toml as safe-to-commit template with placeholder values

Usage

just envs                              # list available profiles
just env mainnet attestor              # switch to mainnet + attestor credentials
just env mainnet trader                # switch to mainnet + trader credentials
just check-balance                     # run example (guards check auth type)
just list-deposits-cc                  # list all deposit addresses
just list-deposits-cc elk-Validator-2  # filtered by owner
just run <any_example_name>            # run any example directly (no guard)

Auth guards automatically check the .env has the right credential type:

• Password-grant recipes (most examples) require KEYCLOAK_USERNAME
• Client-credentials recipes (list-deposits-cc) require KEYCLOAK_CLIENT_SECRET

Test plan

• nu env.nu lists all environments and credentials
• nu env.nu mainnet attestor generates correct .env
• Auth guards block wrong credential type with helpful error message
• just list-deposits-cc works with and without owner filter param
• Error cases (bad env, bad credential, missing credential) show clear messages
• environments.toml no longer contains OWNER_FILTER in any credential profile

🤖 Generated with Claude Code