Non interactive cmd

[HanXHX]

Prepare non interactive usage (CI, scripts... etc).

[Copilot]

Pull request overview

Adds non-interactive / CI-friendly authentication and key handling to the CLI by supporting offline refresh tokens via environment variables, plus optional server-side session revocation on logout.

Changes:

• Extend OIDC discovery/config to include end_session_endpoint and add a revocation call on auth logout.
• Add offline token flow: retyc auth login --offline prints a refresh token for CI, and RETYC_TOKEN enables non-disk auth in GetValidToken.
• Add RETYC_KEY_PASSPHRASE to avoid interactive passphrase prompts and document CI/CD usage in the README.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
internal/config/config.go	Adds EndSessionURL to OIDC config model.
internal/auth/oidc.go	Implements Revoke and supports RETYC_TOKEN env-based token refresh path.
internal/api/login.go	Parses and wires end_session_endpoint from OIDC discovery into config.
cmd/transfer.go	Centralizes key passphrase reading with RETYC_KEY_PASSPHRASE fallback to interactive prompt.
cmd/auth.go	Adds --offline login mode, logout revocation attempt, and offline-token detection helper.
README.md	Documents offline login and CI/CD environment variable usage.

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[HanXHX]

@copilot code review[agent] final review

[Copilot]

@HanXHX I've opened a new pull request, #12, to work on those changes. Once the pull request is ready, I'll request review from you.