# Sprint 255 Execution Tracker - 2026-02-26

## Scope
- `sprint255_plan.md`

## Implemented

New tool:
- `tools/mcp/harden_native_tasks_top_gaps.py`
  - Activates impact profiles from the input spec.
  - Injects required prereq ops, reason keywords, and execution contract fields.
  - Expands task count to profile minimum depth when native output is shallow.

Pipeline integration in `tools/mcp/run_sprint_taskitem_pipeline.sh`:
- Added `WSTONE_NATIVE_RAW_HARDEN_TOP_GAPS` (default `0`).
- Added hardening artifacts:
  - `02af_raw_hardening_input_tasks.json`
  - `02af_raw_hardening_output_tasks.json`
  - `02af_raw_hardening_report.json`
- Added summary packet:
  - `native_raw_hardening`
- Hardening-appended tasks are added to `extra_tasks` effective set for impact coverage evaluation.

## Validation Artifacts

- OFF:
  - `logs/taskitem_runs/TEST_ONLY_sprint255_rawharden_20260226_161923/06_native_impact_coverage.json`
- ON:
  - `logs/taskitem_runs/TEST_ONLY_sprint255_rawharden_20260226_161924/06_native_impact_coverage.json`
  - `logs/taskitem_runs/TEST_ONLY_sprint255_rawharden_20260226_161924/00_summary.json`

Observed result on hard fullstack sample:
- `failing_profile_count: 7 -> 0`
- `taskitems.effective_task_count: 2 -> 6`
- `native_raw_hardening.report.required_ops` includes:
  - `whetstone_generate_taskitems`
  - `whetstone_queue_ready`
  - `whetstone_validate_taskitem`
- `native_raw_hardening.report.required_execution_contract_fields` includes:
  - `deterministic`
  - `rollbackRequired`
  - `replayValidationRequired`

## Explicit Completion Signal

- Sprint 255: `DONE` (implemented + measured uplift on hard sample)