feat: a second preview branch, with secrets from Vault - #8

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4, actions/checkout@v4, actions/setup-dotnet@v4, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Possible null reference argument for parameter 'actual' in 'void ShouldBeStringTestExtensions.ShouldNotContain(string actual, string expected, Case caseSensitivity = Case.Insensitive, string? customMessage = null)'.

Possible null reference argument for parameter 'actual' in 'void ShouldBeStringTestExtensions.ShouldContain(string actual, string expected, Case caseSensitivity = Case.Insensitive, string? customMessage = null)'.

Possible null reference argument for parameter 'actual' in 'void ShouldBeStringTestExtensions.ShouldNotContain(string actual, string expected, Case caseSensitivity = Case.Insensitive, string? customMessage = null)'.

Possible null reference argument for parameter 'actual' in 'void ShouldBeStringTestExtensions.ShouldContain(string actual, string expected, Case caseSensitivity = Case.Insensitive, string? customMessage = null)'.

'PermissionAuthorizationTests.HeaderAuthenticationHandler.Scheme' hides inherited member 'AuthenticationHandler<AuthenticationSchemeOptions>.Scheme'. Use the new keyword if hiding was intended.

Nullability of reference types in type of parameter 'value' of 'bool RecordingHeaders.TryGetHeader(string key, out object? value)' doesn't match implicitly implemented member 'bool Headers.TryGetHeader(string key, out object? value)' (possibly because of nullability attributes).

The using directive for 'ST.DotNetSolutionKit.Samples.Common.Domain.Events' appeared previously in this namespace

Nullability of reference types in return type of 'Task<IActionResult> UnprocessableEntityResultFactory.CreateActionResult(ActionExecutingContext context, ValidationProblemDetails validationProblemDetails, IDictionary<IValidationContext, ValidationResult> validationResults)' doesn't match implicitly implemented member 'Task<IActionResult?> IFluentValidationAutoValidationResultFactory.CreateActionResult(ActionExecutingContext context, ValidationProblemDetails validationProblemDetails, IDictionary<IValidationContext, ValidationResult> validationResults)'.

Possible null reference argument for parameter 'args' in 'void LoggerExtensions.LogDebug(ILogger logger, string? message, params object?[] args)'.

Possible null reference argument for parameter 'args' in 'void LoggerExtensions.LogDebug(ILogger logger, string? message, params object?[] args)'.