Adds `integration_mock_llm.rs` covering the LlmClient trait surface:
- streaming turn loop (text deltas + finish reason)
- reasoning-content replay across tool-call rounds (V4 §5.1.1, the
HTTP 400 path that broke v0.4.9-v0.5.1)
- tool-call round-trip with chunked input JSON
- multiple tool calls in one turn preserve event ordering
- compaction-style non-streaming `create_message`
- sub-agent style independent parent/child mocks
- capacity-gate observation of a captured request
Four full-engine tests are `#[ignore]`-marked as BLOCKED on the engine
refactor from concrete `Option<DeepSeekClient>` to `Arc<dyn LlmClient>`.
Once that wiring lands the ignored tests light up with no mock changes.
Adds:
- `tests/support/llm_client.rs` mirrors the trait so the mock can be
brought into the integration test via `#[path]` without dragging in
the rest of the binary's module tree
- `tests/fixtures/.gitkeep` so the `eval --record` output directory
rides the repo
- `tests/README.md` documents both the trait-level mocking strategy
and the `--record` fixture flow
- `record_flag_writes_one_jsonl_line_per_step` in `eval_harness.rs`
exercises the new `--record` flag end-to-end
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hunter Bown
9db841fc62