[jgarciadelanoceda]

Fixes missing OpenAPI constraints when a property uses ChildRules with an identity rule such as:

ruleBuilder.ChildRules(child =>
    child.RuleFor(x => x)
        .Matches(pattern)
        .DependentRules(() =>
            child.RuleFor(x => x).Must(CountryExists)));

Previously, the library did not associate the identity child rule with its owning property, so the regex pattern was missing from the generated schema.
Changes
• Apply identity child-rule constraints to the owning property or collection item.
• Support nested identity validators while preventing recursive traversal.
• Respect existing rule filters and conditional-rule settings.
• Preserve parent constraints when a runtime-dependent child validator cannot be resolved.
• Update the changelog and add regression tests.
Runtime validation remains unchanged. Extensions can continue accepting IRuleBuilder<T, string> anywhere in the pipeline, and schema generation does not execute Must predicates or repository lookups.
Validation
• All 514 tests passed across supported target frameworks.
• Solution build succeeded.ç

@avgalex. I have tested on my own machine with a local nuget and it works for my scenario.

I have changed an App from CascadeMode.Stop to Continue globally and an extension method I had does 2 validations, the first is almost Nop(Regex) check. The second one is a call to a repository

[avgalex]

Thanks for the fix and for testing it in your application!

During review, I found one edge case: FluentValidation skips child validators when the parent value is null, but propagating an inner NotNull or NotEmpty made that parent property required in OpenAPI.

I pushed a follow-up fix to this PR. It preserves nullable/optional properties while retaining minLength/minItems constraints. Explicit NotNull/NotEmpty rules on the parent still work. I also adjusted NSwag handling so stronger parent length constraints are preserved regardless of rule order.

Added regression coverage across all three OpenAPI backends. All 569 tests pass locally, including 55 new checks. The version and changelog are prepared for 7.2.3.