Make ahnlich-ai extensible (1): Decouple DB

[deven96]

At the moment, the AI proxy is tightly coupled to ahnlich-db. For it to truly be extensible, it would have to be able to

• Return embeddings for raw inputs without having to save within DB. For this, we would have to make an extra endpoint that simply does raw input to embedding conversions and hence doesn't need the binary started with a running DB. Currently we have

let db_client = Self::build_db_client(&config).await
...
AIProxyServer {
    db_client: Arc::new(db_client),
    ...
}
// .. where AIProxyServer struct is 

struct AIProxyServer {
  db_client: Arc<DbClient>,
}

If that is changed to

struct AIProxyServer {
  db_client: Option<Arc<DbClient>>,
 ...
}

and for all queries within the handler that absolutely need it like create_store, throw up an error if db_client is None. Then a new query we can call input_to_embeddings that could look something like

enum AIQuery {
 InputToEmbeddings {
  inputs: Vec<StoreInput>,
  preprocess_action: PreprocessAction,
  model: AIModel,
 },
 ...
}


enum AIServerResponse {
 // Vector of embeddings matching the length of Vec<StoreInput>
 Embeddings(Vec<Array1<f32>>),
 ...
}

A check to then ensure that all StoreInput's input type match the AIModel's input type is sufficient... and finally calling ModelManager::handle_request to return the StoreKey

[opeolluwa]

@deven96 can you assign this to me?