fix(mcp): declare @modelcontextprotocol/sdk as a root dependency (#231)

[jung-thomas]

Fixes #231.

Problem

The hana-cli-mcp bin (./mcp-server/build/index.js) imports @modelcontextprotocol/sdk, but the package only declared it in the nested mcp-server/package.json. npm strips nested node_modules from the published tarball, so registry installs can't resolve it and crash at module resolution — before any config or HANA connection:

$ npx -y -p hana-cli hana-cli-mcp < /dev/null
Error [ERR_MODULE_NOT_FOUND]: Cannot find package '@modelcontextprotocol/sdk'
  imported from .../node_modules/hana-cli/mcp-server/build/index.js

It only worked in a dev checkout, where the nested install made it reachable.

Fix

Add @modelcontextprotocol/sdk@^1.29.0 (the range mcp-server was built against) to the root dependencies. Node's upward module resolution from mcp-server/build/index.js then finds it in the root node_modules of any install. npm-shrinkwrap.json updated accordingly.

Verification

Reproduced the published-tarball state by temporarily removing mcp-server/node_modules, then ran the bin exactly as the issue does:

$ node ./mcp-server/build/index.js < /dev/null
[DocsSearch] Loaded index with 272 documents
[MCP] Loaded 170 command modules from hana-cli
[MCP] Registered 170 unique commands
[MCP] SAP HANA CLI MCP Server running on stdio
EXIT=0

Boots cleanly instead of throwing ERR_MODULE_NOT_FOUND.