Core — Schema

src/core/schema/validator.ts — validateDocument(doc, {strict,maxErrors}) → {valid, errors: {path,code,severity}[]} with JSON Pointer, duplicate-id, table span, latex checks.

src/core/schema/canonical.ts — canonicalStringify (sorted keys), canonicalBytes, contentHash/contentHashHex (sha256).

src/core/normalize/normalize.ts — normalizeDocument, isIdempotent (merge adjacent texts).

src/core/equation/index.ts — validateLatex, latexToHtml, latexToPlainText.

See schemas/portable-doc-v1.json and tests/fixtures/.