JJ: Description from the destination commit:

rename

JJ: Description from source commit:
+ rename

.jjconflict-side-1/src/devices.ml

@@ -0,0 +1,26 @@
+type env = {
+  caqti_switch: Caqti_miou.Switch.t;
+  db_uri: Uri.t;
+}
+
+let db_connection : (env, Caqti_miou.connection) Vif.Device.device =
+  let finally (module Conn : Caqti_miou.CONNECTION) = Conn.disconnect () in
+  Vif.Device.v ~name:"db_connection" ~finally []
+  @@ fun { caqti_switch; db_uri } ->
+  match Caqti_miou_unix.connect ~sw:caqti_switch db_uri with
+  | Error err ->
+      Fmt.failwith "Database connection failure: %a." Caqti_error.pp err
+  | Ok conn -> (
+      match Pg.preflight conn with
+      | Error err ->
+          Fmt.failwith "Database preflight failure: %a." Caqti_error.pp err
+      | Ok () ->
+          Logs.info (fun m -> m "database connection initialized");
+          conn)
+
+let keys =
+  let finally _key = () in
+  Vif.Device.v ~name:"keys" ~finally [ Vif.Device.value db_connection ]
+  @@ fun (module Conn : Pg.CONN) (_env : env) ->
+  let sm : (module Keys.S) = (module Keys.Make (Conn)) in
+  sm