Splits `core/engine.rs` (4670 → 4314 lines) into a small folder module:
- `engine/approval.rs` (~125 lines) — `ApprovalDecision`,
`UserInputDecision`, `ApprovalResult`, plus the two handshake
methods `Engine::await_tool_approval` and `Engine::await_user_input`.
- `engine/dispatch.rs` (~300 lines) — tool-input parsing
(`final_tool_input`, `parse_tool_input`, fenced/JSON segment
helpers), `multi_tool_use.parallel` payload parser, dispatch policy
predicates (`should_parallelize_tool_batch`,
`should_force_update_plan_first`, `should_stop_after_plan_tool`,
the read-only MCP tool helpers), and the
`ToolExecutionPlan`/`ToolExecOutcome`/`ParallelToolResult*`/
`ToolExecGuard` types the batch driver passes around.
The public engine surface (`EngineConfig`, `EngineHandle`,
`spawn_engine`, `MockEngineHandle`, `mock_engine_handle`,
`compact_tool_result_for_context`, `TOOL_CALL_*_MARKERS`,
`FAKE_WRAPPER_NOTICE`) stays in `engine.rs` — every external user
imports unchanged.
Not split this round: the 1268-line `handle_deepseek_turn` method.
Carving its inline parallel/sequential dispatch and approval handshake
arms requires extracting two new methods from a borrow-heavy turn
loop; flagged in the v0.6.0 audit doc as future work.
Workspace tests: 1011/1011 still green. No clippy regressions.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hunter Bown
1a100fe96c