Add support for PiKVM Switch and related features

This commit introduces several new components and improvements:
- Added Switch module with firmware update and configuration support
- Implemented new media streaming capabilities
- Updated various UI elements and CSS styles
- Enhanced keyboard and mouse event handling
- Added new validators and configuration options
- Updated Python version support to 3.13
- Improved error handling and logging

kvmd/validators/__init__.py

@@ -99,3 +99,11 @@ def check_any(arg: Any, name: str, validators: list[Callable[[Any], Any]]) -> An
         except Exception:
             pass
     raise_error(arg, name)
+
+
+# =====
+def filter_printable(arg: str, replace: str, limit: int) -> str:
+    return "".join(
+        (ch if ch.isprintable() else replace)
+        for ch in arg[:limit]
+    )