[saigonbaddielover]

Fixes #3767

The official 2026-07-28 client conformance case sep-2322-client-request-state requires treating an omitted resultType as complete. The SDK currently validates the strict modern wire union first and raises ValidationError, causing an otherwise 5/5-check passing MCPToolset client to exit 1.

Normalize only inbound modern responses missing resultType and not carrying inputRequests / requestState; preserve explicit discriminator values and legacy results. Add seven SDK regressions. Pinned conformance alpha.12: official SDK 32/32 scored client scenarios PASS; PydanticAI MCPToolset directly exercised 4/4 scenarios PASS.

No change to server output or the normative wire profile.

[github-actions]

This PR has been closed automatically. This repo only keeps pull requests open when they come from a maintainer, or from a contributor a maintainer has assigned to the linked issue, and you aren't currently assigned to #3767.

If a maintainer assigns you to #3767, this PR reopens on its own and there's nothing more you need to do here. Assignment is a maintainer call based on capacity; comments that only ask to be assigned don't factor in. What does help is engaging on the issue itself by confirming the repro, explaining why it matters for your use case, or describing the approach you'd take.

You're welcome to keep pushing commits here (just avoid force-pushing, since GitHub can't reopen a rewritten branch), but that on its own won't get the PR reviewed or the issue assigned, and realistically most auto-closed PRs stay closed. There's no need to open a new PR either way.

CONTRIBUTING.md has the full reasoning, but in short:

• We're a small team with very little capacity to review community PRs right now.
• Many recent PRs are AI-generated with little human review, and reviewing one carefully still costs a maintainer as much time as it ever did. A well-described issue is usually more useful to us than the code.

Maintainers: reopen, remove missing-issue-link, or add bypass-issue-check to override.