# Sprint 146 Plan: Language-Neutral Hybrid Core and Capability Matrix

## Context

To make constructive editing production-ready beyond a single language, Sprint
146 establishes language-neutral hybrid contracts and an explicit capability
matrix consumed by all adapters.

---

## Goals

1. Define language-neutral contracts for edit, sync, regeneration, and merge
2. Add explicit capability profiles per language (`cpp`, `rust`, `typescript`, `python`)
3. Remove hidden C++ assumptions from core orchestration models
4. Provide deterministic capability negotiation for tools and agents

---

## Steps

### Step 1699: Hybrid core contract schema v1 (10 tests)
### Step 1700: Language capability matrix model (10 tests)
### Step 1701: Capability negotiation and fallback policy model (10 tests)
### Step 1702: Language-neutral operation envelope model (10 tests)
### Step 1703: `whetstone_list_language_capabilities` MCP tool (8 tests)
### Step 1704: `whetstone_get_language_contract` MCP tool (8 tests)
### Step 1705: `whetstone_validate_language_operation` MCP tool (8 tests)
### Step 1706: Capability decision packet model (8 tests)
### Step 1707: Language capability conformance report artifact (8 tests)
### Step 1708: Sprint 146 integration summary + regression (8 tests)

---

## Architecture Gate

- Core contracts must be language-neutral and deterministic
- Capability negotiation must be explicit, auditable, and reproducible
- Unsupported operations must return structured machine-readable reasons
- Max 600 lines per header