[jongalloway]

Destructive-operation confirmation already supports native MRTR and legacy elicitation, but its coverage did not fully establish wire behavior, solution-removal safety, or the effect of the SDK's retry limits. This closes those verification gaps without changing production confirmation behavior or dependencies.

Changes

• Inspect native inputRequests and submit inputResponses using a transport-only client, independently of the SDK's automatic retry loop.
• Verify legacy Clean and Remove finish within one wire-level tool call, and separately exercise the SDK's explicit-MRTR backward-compatibility resolver.
• Verify real solution membership changes only after accepted boolean confirmation; malformed or missing confirmation data leave Clean and Remove side effects untouched.
• Extend production stdio confirmation coverage to both operations on MCP 2026-07-28 and 2025-11-25.
• Clarify the retained native, legacy, and Tasks paths and document why one confirmation round stays below the SDK's 10-retry limits.

Legacy production calls intentionally retain ElicitAsync; the explicit-MRTR resolver is exercised by a test-only tool. Existing Tasks and no-elicitation fallback behavior remain unchanged.

Validation

• Server build succeeded.
• All 94 targeted elicitation, SDK compatibility, and stdio confirmation tests passed.
• Existing dependency target-framework warnings remain unchanged.

Fixes: #486

[Copilot]

🟢 Approval recommended

There are no active review issues for the expanded destructive-operation confirmation tests and documentation.

No open issues 🎉

What changed in this PR

This PR strengthens verification of destructive-operation confirmation in the .NET MCP server, addressing #486 without changing production behavior or dependencies.

Changes:

• Add native wire-level confirmation tests, solution-removal safety checks, and invalid-response coverage.
• Verify legacy single-call behavior and the SDK’s backward-compatibility resolver; extend real-stdio coverage to both Clean and Remove.
• Document native, legacy, and Tasks confirmation paths and their relationship to SDK retry limits.

File	Description
DotNetMcp.Tests/​Tools/​ElicitationTests.cs	Clarify the fallback test’s name and documentation.
DotNetMcp.Tests/​Server/​Sdk20CompatibilityTests.cs	Add wire-level, side-effect safety, invalid-input, and resolver tests.
DotNetMcp.Tests/​Server/​McpConformanceTests.cs	Cover Clean and Remove confirmation over stdio on both protocols.
doc/​testing.md	Describe the expanded confirmation coverage.
doc/​sdk-v1.1-compatibility.md	Explain confirmation paths and retry limits; update the MRTR documentation link.

_{Review effort: Balanced}