frat: added screen timers_screen, added new buttons: back, delete_timer, new_timer and the functionality is connected to them, udated fuc list_timers() for work with timers_screens for data;

pyproject.toml

@@ -7,7 +7,7 @@ authors = [
 ]
 license = {text = "MIT"}
 readme = "README.md"
-requires-python = ">=3.12"
+requires-python = ">=3.12,<4.0"
 dependencies = [
     "kivy (>=2.3.1,<3.0.0)",
     "pytest (>=8.3.5,<9.0.0)",
@@ -16,6 +16,7 @@ dependencies = [
     "pydantic-settings (>=2.9.1,<3.0.0)",
     "alembic (>=1.15.2,<2.0.0)",
     "ruff (>=0.11.8,<0.12.0)",
+    "kivymd @ https://github.com/kivymd/KivyMD/archive/master.zip",
 ]