Upgrade ranch 1.7.0 → 2.2.0

Ranch 2.x breaking changes addressed:
- Protocol callback changed from start_link/4 (Ref, Socket, Transport, Opts)
  to start_link/3 (Ref, Transport, Opts); socket obtained via ranch:handshake/1
- ranch:info/0 now returns #{Name => #{...}} instead of [{Name, [proplists]}];
  updated mtp_listeners/0, running_ports/0, and config_change_case test

Also update AGENTS.md with CT failure debugging workflow.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

test/mtp_test_middle_server.erl

@@ -6,7 +6,7 @@
 -export([start/2,
          stop/1,
          get_rpc_handler_state/1]).
--export([start_link/4,
+-export([start_link/3,
          ranch_init/1]).
 -export([init/1,
          callback_mode/0,
@@ -63,7 +63,7 @@ get_rpc_handler_state(Pid) ->
 
 %% Callbacks
 
-start_link(Ref, _, Transport, Opts) ->
+start_link(Ref, Transport, Opts) ->
     {ok, proc_lib:spawn_link(?MODULE, ranch_init, [{Ref, Transport, Opts}])}.
 
 ranch_init({Ref, Transport, Opts}) ->

test/single_dc_SUITE.erl

@@ -317,11 +317,11 @@ config_change_case({post, Cfg}) ->
     stop_single(Cfg);
 config_change_case(Cfg) when is_list(Cfg) ->
     %% test "max_connections"
-    MaxConnsBefore = [{Listener, proplists:get_value(max_connections, Opts)}
+    MaxConnsBefore = [{Listener, maps:get(max_connections, Opts)}
                       || {Listener, Opts} <- mtproto_proxy_app:mtp_listeners()],
     NewMaxConns = 10,
     ok = mtproto_proxy_app:config_change([{max_connections, NewMaxConns}], [], []),
-    MaxConnsAfter = [{Listener, proplists:get_value(max_connections, Opts)}
+    MaxConnsAfter = [{Listener, maps:get(max_connections, Opts)}
                      || {Listener, Opts} <- mtproto_proxy_app:mtp_listeners()],
     ?assertNotEqual(MaxConnsBefore, MaxConnsAfter),
     ?assert(lists:all(fun({_Listener, MaxConns}) ->