Part of epic #3602.

Scope

Add a zeph gonka doctor diagnostic subcommand and one #[ignore] live-testnet integration test. Follow-up release — does not block Phase 2 launch.

Files to create / modify

• src/commands/gonka.rs (new) — clap subcommand:
  • zeph gonka doctor — reads vault keys, prints derived address, signs a probe payload against each configured node, reports 2xx / non-2xx with timings.
  • Detects clock skew by reading the Date response header (if 401 contains clock skew, prints local-vs-server delta).
• src/cli.rs — register the new subcommand.
• crates/zeph-llm/tests/gonka_live.rs (new) — single #[tokio::test] #[ignore] test:
  • Reads ZEPH_GONKA_PRIVATE_KEY from env; skips if absent.
  • Round-trips a 1-token chat completion against http://node1.gonka.ai:8000.
  • Asserts non-empty response content.
  • Documented in playbook for the CI cycle.
• .local/testing/playbooks/gonka-native.md — append doctor + live-test scenarios.

Acceptance

• cargo run --features full -- gonka doctor prints address + per-node 2xx report.
• cargo nextest run -p zeph-llm -- --ignored -E 'test(gonka_live)' runs only when env is set.
• Doc page docs/src/llm-providers/gonka.md updated with troubleshooting section pointing to the doctor command.
• CHANGELOG.md [Unreleased] updated.

Depends on

#3613.

Size

M (~4h)