Add probo-agent CLI and deviceagent library

Introduce the standalone device agent binary and shared library
for enrollment, posture checks, self-update, and OS service
integration. Include build targets, module deps, and release
workflow so the agent can ship independently of server changes.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/deviceagent/checks/runcmd_paths_windows.go

@@ -0,0 +1,48 @@
+// Copyright (c) 2025-2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package checks
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func commandCandidates(cmd string) []string {
+	systemRoot := os.Getenv("SystemRoot")
+	if systemRoot == "" {
+		systemRoot = `C:\Windows`
+	}
+	system32 := filepath.Join(systemRoot, "System32")
+
+	switch strings.ToLower(cmd) {
+	case "powershell", "powershell.exe":
+		return []string{
+			filepath.Join(system32, "WindowsPowerShell", "v1.0", "powershell.exe"),
+		}
+	case "manage-bde", "manage-bde.exe":
+		return []string{filepath.Join(system32, "manage-bde.exe")}
+	case "netsh", "netsh.exe":
+		return []string{filepath.Join(system32, "netsh.exe")}
+	case "w32tm", "w32tm.exe":
+		return []string{filepath.Join(system32, "w32tm.exe")}
+	case "sc", "sc.exe":
+		return []string{filepath.Join(system32, "sc.exe")}
+	case "net", "net.exe":
+		return []string{filepath.Join(system32, "net.exe")}
+	default:
+		return nil
+	}
+}