Ephemeral conversations for Ask Ava

Updated the Ask Ava endpoint to better support programmatic consumers like the Terraform provider, MCP server, and CI pipelines.

The sync endpoint created conversations that some automated consumers could not clean up, leading to orphaned conversations in users’ history. The new ephemeral flag lets these callers skip persistence entirely, while the conversationId field enables explicit cleanup for non-ephemeral use cases.

• Added ephemeral: boolean request flag (default false).

  • When set to true: Conversations are not persisted. Recommended for programmatic consumers (Terraform, MCP, CI pipelines).
  • When set to false: Conversations are persisted and the response includes conversationId so callers can manage or delete conversations.

• Changed the response body from a plain string to:

  { "answer": "string", "conversationId": "string (optional)" }