[Server/Client/Protocol] Add developer staff role

Introduce a Developer staff level (proto flag 32, DB admin bit 8) that
sits between admin and moderator: no kick/ban/warn/report/admin powers,
but gets server log access via a new developer command container family
(GET_SERVER_STATS, VIEWLOG_HISTORY) and an idle-timeout exemption.

- Protocol: IsDeveloper flag, developer_commands.proto envelope,
  Command_GetServerStats/Command_GetLogHistory, Response_GetServerStats,
  Command_AdjustMod.should_be_developer
- Servatrice: fail-closed developer dispatcher, uptime snapshot handler,
  shared log history handler reuse, bit-8 DB mapping
- Client: burgundy pawn/badge/labels/sort order, prepareDeveloperCommand,
  minimal Developer stats tab, log tab access, promote/demote actions

Took 24 minutes

Took 18 seconds

libcockatrice_protocol/libcockatrice/protocol/pb/CMakeLists.txt

@@ -22,6 +22,8 @@ set(PROTO_FILES
     command_del_counter.proto
     command_delete_arrow.proto
     command_draw_cards.proto
+    command_get_log_history.proto
+    command_get_server_stats.proto
     command_dump_zone.proto
     command_flip_card.proto
     command_game_say.proto
@@ -71,6 +73,7 @@ set(PROTO_FILES
     context_ready_start.proto
     context_set_sideboard_lock.proto
     context_undo_draw.proto
+    developer_commands.proto
     event_add_to_list.proto
     event_attach_card.proto
     event_change_zone_properties.proto
@@ -140,6 +143,7 @@ set(PROTO_FILES
     response_forgotpasswordrequest.proto
     response_get_admin_notes.proto
     response_get_games_of_user.proto
+    response_get_server_stats.proto
     response_get_user_info.proto
     response_join_room.proto
     response_list_users.proto