feat: add Smartsheet connector

[andrei-hasna]

Summary

• Add @hasna/connect-smartsheet connector package under connectors/smartsheet/
• Implement Smartsheet REST API 2.0 client with Bearer auth covering sheets, rows, columns, folders, workspaces, reports, attachments, discussions, automation, users, contacts, and webhooks
• Register smartsheet in Business Tools category (src/lib/connectors/business-tools.ts)

Acceptance checklist

• Package under connectors/smartsheet/ with @hasna namespace
• Real Smartsheet public API client (https://api.smartsheet.com/2.0)
• CLI entry points (auth, profile, sheets, rows, columns, folders, workspaces, reports, webhooks)
• Types and config utils with multi-profile support
• Placeholder-only .env.example (SMARTSHEET_ACCESS_TOKEN)
• Registry/category update
• No secrets, internal references, or browser-use dependency

Test evidence

cd connectors/smartsheet && bun install && bun run typecheck && bun run build  # pass
bun run typecheck  # pass (repo root)
bun test src/lib/registry.test.ts  # 28 pass
bun test  # 1185 pass, 2 fail (pre-existing: CLI events/whoami — unrelated)
rg beepmedia|hasnaxyz|browser-use connectors/smartsheet  # no matches

Task

Todos: 69fce16a-1bef-4ac9-bc80-719a2ecd2ea7 — Add Alumia connector: smartsheet