Decode the complete HTML Latin-1 entity set

[rogerchappel]

Summary

• add focused regression coverage for the remaining semicolon-terminated HTML Latin-1 named references
• decode fractions, superscripts, operators, punctuation, and the rest of the coherent Latin-1 set
• document the complete supported set and preserve the existing unknown-reference behavior

Commits

• fac228c test: cover remaining Latin-1 entities
• e21fb42 fix: decode complete Latin-1 entity set
• ef15b51 docs: describe Latin-1 entity coverage

Verification

• npm ci --ignore-scripts --no-audit --no-fund
• npm run release:check (43 tests plus syntax, build, CLI smoke, package smoke, and release-contract checks)
• git diff --check origin/main...HEAD

All commit author and committer identities were verified as Roger Chappel <miscanalysis@gmail.com>.

[rogerchappel]

Automated merge note

Triage class: auto-merge

Summary: Completes the semicolon-terminated HTML Latin-1 named-reference set, including fractions and arithmetic symbols, with focused conversion tests and documentation (4 files, +25/-3).

Checks run: CI test completed SUCCESS; isolated npm ci --ignore-scripts --no-audit --no-fund and npm run release:check passed (43 tests, syntax, build, CLI smoke, package smoke, release-contract); git diff --check origin/main...HEAD; final diff, mergeability, branch protection, identities, and head SHA re-verified.

Rebased/CI-repaired: no.

Verified head SHA: ef15b513798416aaad0f585360fea254a5a70f2d.