Step-by-Step Build Order

1. Core Abstractions & Storage Contract: Define RateLimiterStore, RateLimitResult, and Clock in packages/core/.
2. In-Memory Store Implementation: Build lock-free sliding window and token bucket maps in packages/store-memory/.
3. Atomic Redis Lua Engine: Write and test Lua scripts for sliding window counter and token bucket in packages/store-redis/.
4. Rate Limiting Algorithms: Implement mathematical formulas in src/algorithms/.
5. Identity & Cost Resolver: Build client fingerprinting and route normalization in src/identity/.
6. Express 5 Gateway Middleware: Construct non-blocking request interceptor in src/gateway/.
7. React 19 Telemetry UI: Build monitoring dashboard in apps/web/.