# Sprint 156 Plan: Representative Language Runtime Contract Baseline

## Context

Sprint 146-155 added multi-language constructive interfaces, but many handlers
still return scaffold responses. Sprint 156 defines the concrete runtime
contract baseline across representative languages from the 46-120 era.

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## Goals

1. Standardize runtime contract fields across representative languages
2. Define canonical representative language set for constructive operations
3. Establish per-language support tiers and operation coverage matrix
4. Preserve deterministic, machine-readable outputs for all tool responses

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## Steps

### Step 1799: Representative language profile schema (`cpp`, `rust`, `python`, `typescript`, `javascript`, `go`, `java`, `elisp`) (10 tests)
### Step 1800: Cross-language capability contract normalizer model (10 tests)
### Step 1801: Language operation support policy model (`edit`, `sync`, `regenerate`, `merge`, `build_test`) (10 tests)
### Step 1802: Runtime profile store and lookup model (10 tests)
### Step 1803: `whetstone_list_representative_language_profiles` MCP tool (8 tests)
### Step 1804: `whetstone_get_representative_language_profile` MCP tool (8 tests)
### Step 1805: `whetstone_validate_representative_language_operation` MCP tool (8 tests)
### Step 1806: Representative language conformance packet model (8 tests)
### Step 1807: Representative language readiness report artifact (8 tests)
### Step 1808: Sprint 156 integration summary + regression (8 tests)

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## Architecture Gate

- Language outputs must use one shared schema envelope
- Representative language list must be explicit and versioned
- Unsupported operations must return structured denial reasons
- Max 600 lines per header