Add --timeout flag to demo command

[KryptosAI]

What

mcp-observatory demo scans a built-in or discovered MCP server using the default 15s timeout. Some servers (especially ones that need to download packages) take longer and fail unnecessarily.

Add --timeout <ms> flag:

$ mcp-observatory demo --timeout 30000

Files

• src/commands/demo.ts — add .option('--timeout <ms>', 'Timeout in milliseconds', '15000') and pass it to runTarget() via targetConfig.timeoutMs

Acceptance

• --timeout 30000 sets a 30s timeout on the target config
• Default is 15000ms when flag omitted
• Invalid value (non-number) shows clear error