# Sprint 210 Plan: Language-First Efficiency and Reliability Gate

## Context
Language-first path shows high token cost with low hard-spec readiness.

## Goals
1. Add language-first efficiency scoring (tokens vs readiness)
2. Introduce fail-fast guardrails for low-yield runs
3. Route expensive low-yield workloads to deterministic alternatives

## Steps

### Step 2089: Efficiency metric model (10 tests)
Compute token-efficiency score and readiness-adjusted utility.

### Step 2090: Low-yield fail-fast policy (10 tests)
Early-stop language-first runs that exceed token budget with low confidence.

### Step 2091: Route-to-deterministic policy hook (8 tests)
Route to AST-first/deterministic path when efficiency policy fails.

### Step 2092: Efficiency diagnostics and trend report (8 tests)
Emit token-usage trend and low-yield run report artifacts.

### Step 2093: Sprint 210 Integration Summary (8 tests)
Add `editor/src/Sprint210IntegrationSummary.h`.

## Architecture Gate
- Language-first path must satisfy minimum readiness-adjusted efficiency thresholds.