Search memories

curl --request POST \
  --url https://api.case.dev/memory/v1/search \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "query": "investment preferences",
  "filters": {
    "client_id": "client_123"
  },
  "top_k": 5
}
'

{
  "results": [
    {
      "id": "mem_abc",
      "memory": "Client prefers conservative investments",
      "score": 0.92,
      "metadata": {
        "client_id": "client_123"
      }
    }
  ]
}