Add mix task to vacuum the production database

lib/mix/tasks/music_library/prod/db_vacuum.ex

@@ -0,0 +1,19 @@
+defmodule Mix.Tasks.MusicLibrary.Prod.DbVacuum do
+  use Mix.Task
+  @shortdoc "Force VACUUM the production database"
+  @moduledoc """
+  Force VACUUM the production database. This is necessary to make sure that all
+  changes currently in the WAL are persisted to the sqlite database file.
+
+  Requires the `flyctl` CLI to be installed and authenticated.
+  """
+
+  @impl Mix.Task
+  def run(_args) do
+    IO.puts("Running VACUUM on the production database")
+
+    command = ~s(bin/music_library rpc 'MusicLibrary.Repo.query\("VACUUM"\)')
+
+    System.cmd("flyctl", ["ssh", "console", "--command", command], into: IO.stream())
+  end
+end