chore: bump Claude Code to 2.1.51 and Agent SDK to 0.2.51

package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "@actions/core": "^1.10.1",
     "@actions/github": "^6.0.1",
-    "@anthropic-ai/claude-agent-sdk": "^0.2.49",
+    "@anthropic-ai/claude-agent-sdk": "^0.2.51",
     "@modelcontextprotocol/sdk": "^1.11.0",
     "@octokit/graphql": "^8.2.2",
     "@octokit/rest": "^21.1.1",