Fix FT0011/FT0014/FT0015/FT0017 compliance findings in Frends.HTTP.Request

[Copilot]

Resolves 7 task-analyzer findings in Frends.HTTP.Request: missing Success/Error on Result (FT0011), missing <example> tags on Header properties (FT0014), missing ThrowErrorOnFailure/ErrorMessageOnFailure on Options (FT0015), and third-party type exposure on CertificateStoreLocation (FT0017).

Changes

Definitions/

• Header.cs — added <example> tags to Name and Value
• Options.cs — added ThrowErrorOnFailure (default: true) and ErrorMessageOnFailure (default: "")
• Result.cs — added Success and Error properties; consolidated the two success constructors into one internal Result(object body, …) + added internal Result(bool success, Error error) for failure case; failure constructor sets StatusCode = -1 as a sentinel
• Error.cs (new) — Message + AdditionalInfo properties

Helpers/ErrorHandler.cs (new)

Standard error-handler extension following the required platform pattern. Every exception in Request() now routes through it:

catch (Exception ex)
{
    return ex.Handle(options);
}

When ThrowErrorOnFailure = true (default) behavior is identical to before. When false, returns Result { Success = false, Error = { Message, AdditionalInfo } }.

Project / packaging

• Frends.HTTP.Request.csproj: added StyleCop.Analyzers and FrendsTaskAnalyzers references; changed FrendsTaskMetadata.json from None to AdditionalFiles (required for FT0020 to pass)
• Version bumped 1.12.0 → 1.13.0 (non-breaking additions)

Tests

• ErrorHandlerTest.cs (new) — three NUnit tests covering throw-on-failure, return-result-on-failure, and custom error message, using an unreachable URL as the invalid-input trigger

[MatteoDelOmbra]

change type to Exception

[MatteoDelOmbra]

@copilot fix this

[Copilot]

Done — changed AdditionalInfo type from object to Exception in Error.cs (commit $(git rev-parse --short HEAD)).