v1.58.0 — Thuban: typed request-DTO hydration v2 (arrays, source merging, validation hook)

Theme: Typed request-DTO hydration v2. RequestData DTOs gain array & nested-DTO hydration (failing as a clean 422, never a TypeError/500), path/query field merging via #[FromRoute]/#[FromQuery], #[ArrayOf] as the sole array element-type source for request DTOs, a ValidatesSelf cross-field hook, and app-registered custom rules via a built-in-aware RuleRegistry. Fully additive — flat scalar v1 DTOs are byte-identical, with no config or env changes — and closes the request-DTO v1 boundaries shipped in 1.57.0. Minor release; no migrations.

Added

• Typed request-DTO hydration v2 — closes the v1 request-DTO boundaries (the "v1 sharp edges" noted under 1.57.0 no longer apply). RequestData DTOs now hydrate arrays and nested DTOs (failing as 422, never a TypeError/500 — the non-scalar/un-ruled-param sharp edge is gone), pull fields from path/query via #[FromRoute]/#[FromQuery] (v1 was JSON-body-only), declare array element types with #[ArrayOf] (the sole element-type source for request DTOs — @var is not read), run cross-field checks via the ValidatesSelf contract, and resolve app-registered custom rules through a built-in-aware RuleRegistry. Source-attribute misuse (a field with both #[FromRoute] and #[FromQuery], or a source attribute on a nested DTO, or a #[FromRoute] with no route placeholder) fails loud. Flat scalar DTOs are unchanged. See docs/REQUEST_DTOS.md.