App, lib, cmds: Fix mypy.explicit-override fallout

This commit adds @override decorators to approximately 300 methods
across 76 files that inherit from base classes such as AbstractCmd,
FileContext, ExecContext, Distro, SSHClient, and others.

The decorator ensures the type checker can verify that overridden
methods have compatible signatures and prevents accidental shadowing
of inherited methods without intent.

Files modified include command classes, library modules, distro
implementations, and SSH client implementations.

Assisted-by: unsloth/Qwen3.6-35B-A3B-GGUF:IQ4_NL with pi.dev v
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/cmds/projects/check/Cmd.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+from typing import override, TYPE_CHECKING
 
 from ....CmdBase import CmdBase as Base
 from ..CmdCheck import CmdCheck as Parent
@@ -13,6 +13,7 @@ class Cmd(Base):  # export
     def __init__(self, parent: Parent, name: str, help: str) -> None:
         super().__init__(parent, name, help)
 
+    @override
     def add_arguments(self, parser: ArgumentParser) -> None:
         super().add_arguments(parser)