chore: prepare 0.7.0 release with audit fixes

[rlippmann]

Summary

• Bumps package version to 0.7.0.
• Applies npm audit fix updates.
• Includes final readability polish in docs/examples, including helper/constant usage in example material where it improves clarity.

Why

Prepare the TypeScript port for the 0.7.0 release with updated package metadata, dependency audit remediation, and final docs readability cleanup.

Scope checklist

• Diff is minimal and scoped to the requested behavior
• Python/spec parity is preserved (or mismatch is explicitly documented)
• Fixture semantics are respected (exact string vs non-empty null rule)
• No unrelated refactors
• Relevant validation was run (npm test for behavior changes, or docs-only/no-runtime-change)

Notes

Validation details:

• npm test: failed due known flaky local build-cleanup issue in tests/demos-smoke.test.ts (rm: dist: Directory not empty) while the test suite triggers an internal build.
• npm run build: passed
• If not run, why: n/a