feat: Allow infinite reconnect retries with -1 setting

Enable supavisor to maintain connections when the database
is intentionally down. This supports external systems that
dynamically start and scale database instances based on
supavisor metrics, allowing for "scale to zero" scenarios.

lib/supavisor/db_handler.ex

@@ -110,7 +110,7 @@ defmodule Supavisor.DbHandler do
       ]
 
     maybe_reconnect_callback = fn reason ->
-      if data.reconnect_retries > @reconnect_retries and data.client_sock != nil,
+      if @reconnect_retries != -1 and data.reconnect_retries > @reconnect_retries and data.client_sock != nil,
         do: {:stop, {:failed_to_connect, reason}},
         else: {:keep_state_and_data, {:state_timeout, reconnect_timeout(data), :connect}}
     end