[APP] Alive5 SMS

**Name of app / service**
Alive5, https://www.alive5.com. I work at Alive5 and am developing our SMS integration.

**Link to developer documentation**
https://www.alive5.com/api
https://www.alive5.com/alive5-public-api

**Is lack of support preventing you from moving forward, or do you have a workaround?**
Yes. Alive5 is not registered as a Pipedream app, so our connector needs an app/auth definition before its components can use connected accounts. We are building registry components and will link the pull request here.

Authentication is a single API key, entered as a secret field named `api_key`, sent as the `X-A5-APIKEY` HTTP header. Base URL: `https://api.alive5.com/public/1.0`. A read-only authentication test is `GET /objects/channels-and-users/list`. Check the JSON `code` and `error` envelope in addition to HTTP status. API keys are available in the Alive5 dashboard settings. Please register the app slug as `alive5`.

**Are there specific actions or triggers you'd like to see for this app?**
- Send SMS, with dynamic business-number and sending-user selections.
- New SMS Received, an instant webhook trigger with automatic registration and cleanup.
- List Channels and Users, for account setup and mapping.

The webhook uses Alive5's per-number SMS interceptor API. It can post directly to a Pipedream source URL; no external relay or extra credentials are required. Alive5 currently makes one delivery attempt and does not emit image-only messages. Those service limits will be documented in the connector.

Start with the Alive5 API documentation and the read-only GET /objects/channels-and-users/list endpoint, verifying both its HTTP status and JSON code/error envelope. The work is complete when the app is registered as alive5 with api_key authentication and the requested SMS, webhook, and channels/users components support the documented service limits.

Written by the indexing model from the issue text.