Misc indexing improvements (#99)

* increased file follower timeout to 10 minutes

* Removed unique index across a source's collection and its media profile

* Ensure source gets updating during slow indexing

priv/repo/migrations/20240320181210_remove_unique_index_from_sources.exs

@@ -0,0 +1,7 @@
+defmodule Pinchflat.Repo.Migrations.RemoveUniqueIndexFromSources do
+  use Ecto.Migration
+
+  def change do
+    drop unique_index(:sources, [:collection_id, :media_profile_id])
+  end
+end