Add versioned CTRF schema validation

[Ma11hewThomas]

Updates ctrf-js to support validation against every published CTRF specification version:

• 0.0.1
• 0.0.2
• 0.0.3
• 0.0.4
• 0.1.0
• latest, which resolves to 0.1.0

Each schema is copied exactly from its corresponding CTRF release. Schema loading now uses the complete semantic version so patch releases can have distinct validation behaviour.

Retry-history validation is version-aware: the stricter rules apply to 0.0.4 and 0.1.0, while earlier versions retain their historical behaviour.

This change also:

• Sets 0.1.0 as the current and default specification version.
• Adds version selection to validate(), isValid(), and validateStrict().
• Exports SchemaSelector and SupportedSpecVersion.
• Updates builders, merging, documentation, and generated API references.
• Prepares ctrf-js 0.4.0.

Verification

• All 230 tests pass.
• Type checking, linting, formatting, documentation, and ESM/CJS builds pass.
• Every bundled schema is byte-for-byte identical to its corresponding CTRF release.
• Package validation reports no type or export problems.
• The package contains all five versioned schemas.