Frends.JSON.Query: fix compliance findings (net8, static class, CancellationToken, error handling)

[Copilot]

Resolves five task-analyzer findings (FT0004, FT0007, FT0011, FT0015 ×2) plus csproj compliance gaps in Frends.JSON.Query. Bumps target framework to net8 and version to 1.3.0.

csproj

• Frends.JSON.Query.csproj: net6.0 → net8.0, version 1.2.0 → 1.3.0
• Frends.JSON.Query.UnitTests.csproj: net6.0 → net8.0, added <PackageProjectUrl> and <Product>Frends</Product> (the UnitTests suffix is not matched by the *.Test*.csproj exclude pattern)

Definitions

• Options: added ThrowErrorOnFailure (bool, default true) and ErrorMessageOnFailure (string, default "") — FT0015
• Error (new): Message + AdditionalInfo (Exception)
• Result: added Error property; added internal constructor for the failure path — FT0011

Task class (Query.cs)

• JSON made static — FT0004
• Query gains a CancellationToken parameter — FT0007
• Method body wrapped in try/catch following the standard ErrorHandler pattern:
  • OperationCanceledException is always rethrown
  • Other exceptions: thrown (wrapped) when ThrowErrorOnFailure = true (default, preserves existing behaviour); returned as Result { Success=false, Error=… } when false

// New signature
public static Result Query(
    [PropertyTab] Input input,
    [PropertyTab] Options options,
    CancellationToken cancellationToken)

// Non-throwing path
var options = new Options { ThrowErrorOnFailure = false };
var result = JSON.Query(input, options, cancellationToken);
// result.Success == false, result.Error.Message populated

Tests

• Existing calls updated with CancellationToken.None
• QueryShouldThrowIfOptionSetAndFilterMatchesNothing updated to assert Exception (error handler wraps the original JsonException)
• Added QueryShouldReturnErrorResultWhenThrowErrorOnFailureIsFalse

[MichalFrends1]

@copilot use Result Handle method that was provided in initial prompt instead this code in main method for error handler options. You can also remove newly added constructor with error and add error filed to current constructor, or remove both constructors if they are not needed.

[Copilot]

Done in the latest commit. The inline error handling has been extracted into a new Helpers/ErrorHandler.cs following the standard Handle extension method pattern. Query.cs now simply calls ex.Handle(options) in the catch block, and the success path uses an object initializer. Both Result constructors were removed — all three properties now use internal set, which is what allows ErrorHandler to use the object initializer syntax.

[MichalFrends1]

@copliot instead of this test please create new error handler class same like this one: https://github.com/FrendsPlatform/Frends.Smb/blob/main/Frends.Smb.WriteFile/Frends.Smb.WriteFile.Tests/ErrorHandlerTest.cs