test: move comprehensive TestGetToolsets to app package

Replace simple test with comprehensive version that verifies
specific toolset names are present. This test was previously
in cmd/stackrox-mcp/main_test.go and is now in the proper
location alongside the GetToolsets function.

Addresses PR #50 review comment #3

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: janisz

internal/app/app_test.go

@@ -3,31 +3,19 @@ package app
 import (
 	"testing"
 
+	"github.com/stackrox/stackrox-mcp/internal/client"
 	"github.com/stackrox/stackrox-mcp/internal/config"
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 func TestGetToolsets(t *testing.T) {
-	cfg := &config.Config{
-		Central: config.CentralConfig{
-			URL: "https://example.com",
-		},
-		Tools: config.ToolsConfig{
-			ConfigManager: config.ToolConfigManagerConfig{
-				Enabled: false,
-			},
-			Vulnerability: config.ToolsetVulnerabilityConfig{
-				Enabled: true,
-			},
-		},
-	}
+	allToolsets := GetToolsets(&config.Config{}, &client.Client{})
 
-	// We can't create a real client without a valid connection,
-	// so we pass nil and just test that getToolsets returns something
-	toolsets := getToolsets(cfg, nil)
+	toolsetNames := []string{}
+	for _, toolset := range allToolsets {
+		toolsetNames = append(toolsetNames, toolset.GetName())
+	}
 
-	require.NotNil(t, toolsets, "getToolsets should return a non-nil slice")
-	assert.NotEmpty(t, toolsets, "getToolsets should return at least one toolset")
-	assert.Len(t, toolsets, 2, "getToolsets should return 2 toolsets")
+	assert.Contains(t, toolsetNames, "config_manager")
+	assert.Contains(t, toolsetNames, "vulnerability")
 }