fix: default values in subordinate entities based on static_filtering, add: button visibility callbacks in entities' forms

bot/handlers/editors/date.py

@@ -54,6 +54,9 @@ async def time_picker(
 ):
     keyboard_builder = InlineKeyboardBuilder()
 
+    if not current_value:
+        current_value = time(0, 0)
+
     for i in range(12):
         keyboard_builder.row(
             InlineKeyboardButton(