Docs/examples: prefer camelCase API usage in TypeScript

[rlippmann]

Summary

• Update user-facing TypeScript docs/examples/demos to prefer camelCase API names where aliases are available.
• Keep implementation behavior unchanged; this is an ergonomics/docs usage update only.
• Preserve snake_case support for parity/compatibility without using it as the default in TS-facing guidance.

Why

• The TS package now exposes camelCase aliases for snake_case public APIs.
• User-facing TS guidance should default to idiomatic TS naming for readability and consistency.
• This reduces confusion for TS users while preserving Python parity compatibility.

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

• Updated files include README, demos, examples, and integration example code paths.
• No fixture files were modified.
• No runtime behavior changes were introduced.

Validation details:

• npm test: passed
• If not run, why: n/a