Add device agent library

Provide enrollment, elevated install, posture checks, keystore, and
system-tray helpers shared by the probo-agent binary.

Signed-off-by: Ludovic Vielle <ludovic@probo.com>

pkg/deviceagent/tray/console_user_windows_test.go

@@ -0,0 +1,128 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.com>.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+//go:build windows
+
+package tray
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsInteractiveUserSID(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name string
+		sid  string
+		want bool
+	}{
+		{
+			name: "domain user sid",
+			sid:  "S-1-5-21-1234567890-123456789-123456789-1001",
+			want: true,
+		},
+		{
+			name: "entra user sid",
+			sid:  "S-1-12-1-3603547745-1252762009-756918658-301435180",
+			want: true,
+		},
+		{
+			name: "entra authority without user subauthority",
+			sid:  "S-1-12-2-3603547745-1252762009-756918658-301435180",
+			want: false,
+		},
+		{
+			name: "bare entra authority prefix",
+			sid:  "S-1-12-",
+			want: false,
+		},
+		{
+			name: "local system sid",
+			sid:  "S-1-5-18",
+			want: false,
+		},
+		{
+			name: "builtin administrators sid",
+			sid:  "S-1-5-32-544",
+			want: false,
+		},
+		{
+			name: "empty sid",
+			sid:  "",
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(
+			tt.name,
+			func(t *testing.T) {
+				t.Parallel()
+
+				assert.Equal(t, tt.want, isInteractiveUserSID(tt.sid))
+			},
+		)
+	}
+}
+
+func TestAppendUniqueSessionID(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		ids       []uint32
+		sessionID uint32
+		want      []uint32
+	}{
+		{
+			name:      "append to empty slice",
+			ids:       nil,
+			sessionID: 2,
+			want:      []uint32{2},
+		},
+		{
+			name:      "append new session",
+			ids:       []uint32{1},
+			sessionID: 2,
+			want:      []uint32{1, 2},
+		},
+		{
+			name:      "skip duplicate session",
+			ids:       []uint32{1, 2},
+			sessionID: 2,
+			want:      []uint32{1, 2},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(
+			tt.name,
+			func(t *testing.T) {
+				t.Parallel()
+
+				got := appendUniqueSessionID(tt.ids, tt.sessionID)
+				assert.Equal(t, tt.want, got)
+			},
+		)
+	}
+}