The real `jarvis ask --agent opencode` path passes an InstrumentedEngine
(telemetry wrapper) whose underlying engine — and its `_host` — lives at
`_inner`. The base-URL derivation only checked the top object, so it returned
"", no provider was registered, and opencode 500'd on `openjarvis/<model>`.
Direct construction with a raw engine masked this; only the CLI path exposed
it.
- _derive_openai_base_url now unwraps up to 6 wrapper layers
(`_inner`/`_engine`/`_wrapped`) to find `_host`/`base_url`.
- run() resolves the provider/model spec up front and, when it genuinely
can't (no base URL + bare model name), returns a clear actionable error
instead of letting opencode 500.
Tests: wrapper-unwrap derivation + unresolvable-provider guard. 20 passed,
ruff clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
