Get a dashboard connection handoff for one platform

Example response

{
  "connect": {
    "platform": "telegram",
    "aliases": [],
    "label": "Telegram",
    "status": "supported",
    "method": "manual_credentials",
    "provider_platforms": [
      "telegram"
    ],
    "dashboard_url": "https://www.poster.ly/dashboard/connect?platform=telegram",
    "connection_url": "https://www.poster.ly/dashboard/connect?platform=telegram",
    "oauth_url": null,
    "supports_direct_oauth_url": false,
    "supports_direct_credentials": true,
    "credentials_endpoint": "/api/v1/connect/telegram/credentials",
    "requires_browser_session": false,
    "configured": true,
    "env_requirements": [],
    "missing_env": [],
    "scopes": [],
    "credential_fields": [
      {
        "key": "bot_token",
        "label": "Bot token",
        "type": "password",
        "required": true,
        "description": "Telegram bot token from BotFather."
      },
      {
        "key": "chat_id",
        "label": "Chat ID",
        "type": "text",
        "required": true,
        "description": "Target channel or group chat ID."
      }
    ],
    "notes": [
      "The dashboard opens a credential form instead of redirecting to OAuth.",
      "Supports headless connection: POST the credential_fields to /api/v1/connect/telegram/credentials with accounts:write, no browser session needed. The dashboard credential form and connect sessions keep working too.",
      "Use connection_url in a logged-in browser, or create a connect session with POST /api/v1/connect/{platform}/sessions for pollable agent progress. Direct public OAuth URL generation is intentionally not exposed because provider callbacks depend on short-lived browser state."
    ],
    "connected_count": 0,
    "connected_accounts": []
  }
}