refactor: move client info handling to desktop-specific files

Move client information related functions from client_info_*.go to desktop_*.go files
to better organize platform-specific code and separate desktop functionality from
shared code.

No functional changes.

desktop_windows.go

@@ -1,7 +1,22 @@
 package ctrld
 
+import "golang.org/x/sys/windows"
+
 // IsDesktopPlatform indicates if ctrld is running on a desktop platform,
 // currently defined as macOS or Windows workstation.
 func IsDesktopPlatform() bool {
 	return isWindowsWorkStation()
 }
+
+// SelfDiscover reports whether ctrld should only do self discover.
+func SelfDiscover() bool {
+	return isWindowsWorkStation()
+}
+
+// isWindowsWorkStation reports whether ctrld was run on a Windows workstation machine.
+func isWindowsWorkStation() bool {
+	// From https://learn.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-osversioninfoexa
+	const VER_NT_WORKSTATION = 0x0000001
+	osvi := windows.RtlGetVersion()
+	return osvi.ProductType == VER_NT_WORKSTATION
+}