Bump @modelcontextprotocol/conformance pin from 0.1.16 to 0.2.0-alpha.2

The latest published prerelease (0.2.0-alpha.2, Jun 3 2026) adds gated scenarios
for SEP-2243 (HTTP headers), SEP-2549 (caching), and SEP-2322 (MRTR/incomplete
result). Pinning to it makes the 14 currently-skipped scenarios available to
HasSep2243Scenarios()/HasCachingScenario()/HasMrtrScenarios().

However, alpha.2 still ships the placeholder wire string 'DRAFT-2026-v1' for
draft scenarios, while this SDK (and the conformance main branch, awaiting
alpha.3 publish) emits the spec-ratified '2026-07-28'. Without an additional
gate, the 14 newly-activated scenarios all fail with mismatched draft wire
strings. The next commit tightens the gates with a HasMatchingDraftWireVersion()
guard so they remain skipped on alpha.2 and activate on alpha.3+ (or on a local
build of conformance main installed via 'npm install --no-save').

Baseline test surface unchanged: 126 pass / 14 skip / 2 pre-existing skip in
ConformanceTests on net9.0 (one pre-existing failure in
HttpHeaderConformanceTests.Server_RejectsInvalidUtf8EncodedHeaderValue predates
this change).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: halter73

package-lock.json

@@ -2,7 +2,7 @@
   "private": true,
   "description": "Pinned npm dependencies for MCP C# SDK integration and conformance tests",
   "dependencies": {
-    "@modelcontextprotocol/conformance": "0.1.16",
+    "@modelcontextprotocol/conformance": "0.2.0-alpha.2",
     "@modelcontextprotocol/server-everything": "2026.1.26",
     "@modelcontextprotocol/server-memory": "2026.1.26"
   }