✨ feat: Add the Classification Port

[danny-avila]

What

src/classification/: the classification port — typed questions (boolean, choice, score) about a piece of content, answered by a classifier with a probability per answer — as an SDK module, so LibreChat (packages/api, PR LibreChat-AI/LibreChat#16180), codegraph and any other consumer import one implementation instead of carrying copies.

Why

PR #16180 put the port in packages/api; codegraph mirrored it in plain ESM to run on a dev box; both now answer through TypeSafe's Jev. The SDK is where the shared contract belongs: consumers keep their configuration (librechat.yaml, an env file), the SDK keeps the wire dialect, the transport and the presets.

Shape

src/classification/
  types.ts        questions, answers, Classifier, ClassificationError, dialect + provider settings
  dialect.ts      boolean <-> noul; string criterion -> {true} pair; reads boolean/choice/score answers
  transport.ts    one deadline per call, bounded retries (429/5xx/network, retry-after <= 10 s), onAnswered hook
  http.ts         createHttpClassifier / parseEnvelope (requestKey / responseKey for hosts that nest)
  presets.ts      typesafe, openrouter, cloudflare, http; createClassifier(settings, apiKey, { fetch })
  questions.ts    booleanQuestion, choiceQuestion, scoreQuestion
  index.ts        exports (also re-exported from src/index.ts)
  classification.test.ts   7 tests, fake fetch

Differences from #16180: score questions and answers (TypeSafe supports them; codegraph's issue severity uses them); boolean criteria accept a string for the yes side and normalise to the {true, false} pair; no librechat-data-provider or @librechat/data-schemas import (an onAnswered(label, ms) hook replaces the logger).

Checks run

• npx jest src/classification — 7 passed
• npx tsc --noEmit -p tsconfig.json — clean
• node scripts/sort-imports.ts src/classification/*.ts — applied

Draft: publishing is a version bump; #16180 rebases onto the import afterwards, and codegraph's suppliers/classify/port.mjs becomes an import.