Validates and folds each route argument's constraints against the argument type's constraint schema, exactly like Ash does for resource attributes and action arguments.

This normalizes route arguments to the same shape as manifest inputs at the source: type constraint defaults (e.g. allow_empty?: false, trim?: true for strings) are made explicit, so every downstream consumer — the request handler's constraint application, TS type mapping, and the shared Zod/ Valibot field composition in SchemaCore — sees identical data regardless of whether a field originated from an RPC action or a typed controller.

Invalid constraints (typos, wrong option types) become compile-time errors, matching Ash's behavior for resource arguments.