Summary

• reject malformed TRUSTED_PROXY_COUNT values instead of partially accepting them via parseInt
• reuse the shared getClientIp implementation from middleware to avoid drift
• add focused tests for trusted proxy parsing and X-Forwarded-For selection

Validation

• vitest run src/lib/server/rate-limiter.test.js
• node --check src/lib/server/rate-limiter.js
• node --check src/middleware.js
• git diff --check