# Sprint 175 Plan: Real Adapter Binding for Constructive Step Runtime

## Context
`docs/constructive_editing_runtime_plan.md` Phase A calls for replacing synthetic
constructive-step outcomes with real adapter execution across representative
languages.

## Goals
1. Bind constructive-step MCP tools to real adapter operations
2. Preserve existing response envelopes while attaching real evidence
3. Keep deterministic fallback for unsupported operations

## Steps

### Step 1914: Bind `whetstone_run_constructive_step` to adapter execution (12 tests)
Primary files:
- `editor/src/mcp/RegisterSprint152Tools.h`
- `editor/src/graduation/RepresentativeLanguageRuntime.h`
- `editor/src/CppConstructiveEditAdapter.h`
- `editor/src/RustGoConstructiveEditAdapter.h`
- `editor/src/PythonTypeScriptConstructiveEditAdapter.h`

Tests (12): cpp/rust/python/typescript execution path coverage, unsupported op
fallback, deterministic operation ordering, stable mutation packet shape, error
mapping consistency, strict-mode behavior, and permission enforcement.

### Step 1915: Real adapter diagnostics in status tool (10 tests)
Update status surfaces to report adapter-native diagnostics and outcome metadata.

Tests (10): status schema validity, adapter diagnostic field presence, deterministic
sorting, partial failure handling, empty-diagnostic behavior, and backward
compatibility with previous payload shape.

### Step 1916: Real stage outcomes in constructive loop (10 tests)
`whetstone_run_constructive_loop` records real adapter outcomes per stage.

Tests (10): per-stage evidence payloads, iteration stability, resumable state,
blocked/green semantics, and no silent success in strict mode.

### Step 1917: Deterministic fallback policy for unsupported operations (8 tests)
Formalize fallback path with explicit reason codes and trace entries.

Tests (8): fallback trigger correctness, reason-code schema, trace determinism,
retry bounds, and non-supported-language handling.

### Step 1918: Sprint 175 Integration Summary (8 tests)
Add `editor/src/Sprint175IntegrationSummary.h`.
Record:
- `steps_completed=5`
- `constructive_step_bound_to_real_adapters=true`
- `constructive_status_reports_real_diagnostics=true`
- `constructive_loop_records_real_stage_outcomes=true`
- `success=true`

## Architecture Gate
- Constructive-step success must be grounded in real adapter execution evidence
- Unsupported operations must return explicit deterministic fallback metadata