#25: handle MCP startup failure with catch handler

[VasilevNStas]

Problem:
The top-level IIFE in index.ts awaits server.connect() without a .catch() handler. On Node >=18, unhandled promise rejections terminate the process with no diagnostic output.

Solution:
Attach .catch() that logs the error context via console.error and exits with code 1. Add regression test that mocks server.connect rejection and asserts proper error reporting and exit.

Checklist:

• npx eslint . — 0 errors
• npx jest --coverage — all pass, coverage >=90%
• npx tsc --target es2020 --module nodenext --outDir dist — 0 errors
• make — lint + test + it + tsc pass

[VasilevNStas]

@yegor256 @edmoffo please review

[kreinba]

Attaching .catch() to the top-level IIFE logs the rejection and exits with a non-zero code, the new test mocks server.connect rejection and asserts console.error and process.exit calls, jest and eslint pass locally. Resolves #25. 0 inline comments.

[VasilevNStas]

@yegor256 @edmoffo please re-review