Typecheck the three test workspace packages, and fix the registerPrompt typing defect they were hiding - #2841

{ "workflowData": { "owner": "modelcontextprotocol", "repo": "typescript-sdk", "sha": "5a74dc90422abeb32e3bc87e08ed5bd8dfb49baf", "ref": "2841", "headBranch": null }, "key": "qWoWdzeYYb", "runId": 35650303533, "webhookDebug": { "action": "requested", "head_branch": "fix/typecheck-test-packages", "head_repository_full_name": "sharziki/typescript-sdk", "full_name": "modelcontextprotocol/typescript-sdk", "isPullRequest": true, "prNumber": 2841, "prNumberType": "number", "isNewPullRequest": true, "isOldPullRequest": false, "prKey": "sharziki/typescript-sdk:fix/typecheck-test-packages", "oldPrDataHash": "T14QiOH9xU", "lookupKey": "sharziki/typescript-sdk:fix/typecheck-test-packages", "data": { "owner": "modelcontextprotocol", "repo": "typescript-sdk", "sha": "5a74dc90422abeb32e3bc87e08ed5bd8dfb49baf", "ref": "2841", "headBranch": null } }, "currentCursor": { "sha": "0efee44638a569b5e80503027e29ce020fedcf67", "timestamp": 35641247527 }, "pkgPrNewVersion": "0.0.88" }