Improve system information retrieval for macOS and Windows

- Introduce `Os` enum to represent supported operating systems.
- Update `SystemInfo` interface to include OS type.
- Refactor `ContainerChart` component to use `ChartType` enum for better clarity.
- Switched to dynamic units in container memory chart.

beszel/site/src/lib/enums.ts

@@ -0,0 +1,13 @@
+export enum Os {
+	Linux = 0,
+	Darwin,
+	Windows,
+	// FreeBSD,
+}
+
+export enum ChartType {
+	Memory,
+	Disk,
+	Network,
+	CPU,
+}