Upgrade MCP SDK to 1.29

[itz4blitz]

Summary

Upgrades @modelcontextprotocol/sdk from ^1.6.0 to ^1.29.0 and hardens the MCP smoke test with wire-contract assertions so future SDK bumps are verified against the actual protocol surface.

Changes

• package.json / package-lock.json: @modelcontextprotocol/sdk ^1.6.0 → ^1.29.0. No other dependency or version changes.
• scripts/mcp-smoke-test.mjs: new wire-contract assertions on top of the existing tool/resource/prompt checks:
  • Initialize handshake: server must identify as name: "linear" with a semver version, and declare the tools, resources, and prompts capabilities.
  • Advertised tool list must contain no duplicate names.
  • Tool-result shape: a successful linear_getServerStatus call (no Linear I/O required) must return a content array of text items with isError: false, and its JSON payload must report the advertised tool count and a semver version.
  • In-band error shape for invalid arguments: calling linear_getServerStatus with an unknown argument must return isError: true with a text content item (Unknown argument(s) for ...), not a protocol-level error.
  • In-band error shape for unknown tools: calling a nonexistent tool must return isError: true with Unknown tool: ..., not a protocol-level error.

Breaking changes handled

None required. The server compiles and runs against SDK 1.29 without source changes — the Server, StdioServerTransport, request-schema handler registration, and client APIs used here are all compatible across 1.6 → 1.29.

Verification

All checks run against SDK 1.29 on this branch:

• npx jest: 25 suites, 172 tests passed
• npm run build (tsc): clean
• npm run test:mcp-smoke: passed — 185 tools, 6 resources, 4 prompts, plus all new wire-contract assertions
• npm pack --dry-run: clean
• git diff --check: clean

The new smoke-test assertions were also validated against the old SDK (1.6) before the upgrade to confirm they encode existing behavior rather than 1.29-specific behavior.