Add TypeDoc API docs, coverage reporting, and benchmarks

[larkiny]

Summary

• TypeDoc + JSDoc: Added JSDoc comments to all 12 exported functions/interfaces, configured TypeDoc to generate HTML API docs, and added a CI job to deploy to GitHub Pages on push to main
• Coverage reporting: Added @vitest/coverage-v8 so the test-ts CI job prints a coverage table in the logs (no external service)
• Performance benchmarks: Added ts/detect.bench.ts with small file (100 lines) and large file (10k lines) benchmarks for detectBip39Sequences, plus an informational CI job

Post-merge action

Enable GitHub Pages in repo settings: Settings → Pages → Source: GitHub Actions

Test plan

• All 77 tests pass with coverage enabled
• pnpm run docs generates docs-site/ without errors
• pnpm run bench produces benchmark table
• pnpm run lint && pnpm run format:check clean
• CI passes (lint, test-ts with coverage, test-bash, test-install, bench jobs)
• After merge: enable GitHub Pages and verify docs at larkiny.github.io/nomonic/