.NET: Cover source-type-agnostic toolbox consent parsing (a2a_preview)

[rogerbarreto]

Motivation & Context

Issue #7227 reports that the Python Foundry hosting consent parser only recognizes a
consent requirement when the toolbox source type is mcp. Work IQ identifies its
source as a2a_preview, so the Python parser returns None and the hosted agent never
surfaces the oauth_consent_request to the client.

The .NET Microsoft.Agents.AI.Foundry.Hosting package already avoids that trap: consent
detection keys off the JSON-RPC error semantics only, never the tool source type.
ToolboxConsentParser.TryParseConsentRequired walks the embedded errors[] array and
matches on the nested error.code == "CONSENT_REQUIRED", and the per-tool-call path in
ConsentAwareMcpClientAIFunction intercepts on JSON-RPC code -32006 alone. Both are
source-type agnostic, so the Work IQ a2a_preview scenario works on .NET today.

The existing unit tests all happened to use type: mcp, so nothing actually pinned the
source-agnostic guarantee. This PR adds coverage so the behavior cannot silently regress.

Description & Review Guide

What are the major changes?

• Added a [Theory] to ToolboxConsentParserTests that asserts consent is surfaced for
  mcp, a2a_preview (the Work IQ case from .NET: Python: [Bug]: ResponsesHostServer does not surface Work IQ CONSENT_REQUIRED from a2a_preview source #7227), and an arbitrary future source type.

What is the impact of these changes?

• Test-only. No production code changes. Locks in the source-type-agnostic consent
  parsing that already exists in .NET so a future edit cannot reintroduce a type == "mcp"
  restriction like the one Python hit.

What do you want reviewers to focus on?

• Confirm the added theory cases reflect the real proxy payload shape from .NET: Python: [Bug]: ResponsesHostServer does not surface Work IQ CONSENT_REQUIRED from a2a_preview source #7227.

Related Issue

Contributes to #7227 (the .NET side; the Python parser fix is tracked separately in the
same issue).

Contribution Checklist

• I have read the Contributing Guidelines and my code adheres to them
• The code builds clean without any errors or warnings
• I didn't break anyone. All existing tests pass
• This is not a breaking change.

[github-actions]

Automated Code Review

Reviewers: 5 | Confidence: 95% | Result: All clear

Reviewed: Correctness, Security Reliability, Test Coverage, Failure Modes, Design Approach

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Automated review by rogerbarreto's agents

[Copilot]

Pull request overview

Adds .NET unit-test coverage to lock in that Foundry toolbox OAuth-consent detection is source-type agnostic (i.e., it relies on the nested CONSENT_REQUIRED semantics, not errors[].type). This prevents a future regression that would miss consent requirements for non-mcp toolbox sources such as Work IQ’s a2a_preview (issue #7227).

Changes:

• Added an xUnit [Theory] covering type: "mcp", type: "a2a_preview", and an arbitrary future type.
• Asserts ToolboxConsentParser.TryParseConsentRequired(...) returns a single consent entry with the expected toolbox name, tool/source name, and consent URL for all source types.

[github-actions]

Automated Code Review

Reviewers: 5 | Confidence: 95% | Result: All clear

Reviewed: Correctness, Security Reliability, Test Coverage, Failure Modes, Design Approach

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Automated review by rogerbarreto's agents