fix: resolve goimports formatting issues

Fix import formatting violations detected by golangci-lint in:
- internal/config/config.go
- internal/tui/tui.go
- internal/tui/tui_test.go

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: Brandon H

internal/config/config.go

@@ -5,8 +5,9 @@ import (
 	"os"
 	"path/filepath"
 
-	"gopkg.in/yaml.v3"
 	"hosts-manager/pkg/platform"
+
+	"gopkg.in/yaml.v3"
 )
 
 type Config struct {

internal/tui/tui.go

@@ -7,7 +7,7 @@ import (
 	"hosts-manager/internal/config"
 	"hosts-manager/internal/hosts"
 
-	"github.com/charmbracelet/bubbletea"
+	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
 )
 

internal/tui/tui_test.go

@@ -7,7 +7,7 @@ import (
 	"hosts-manager/internal/config"
 	"hosts-manager/internal/hosts"
 
-	"github.com/charmbracelet/bubbletea"
+	tea "github.com/charmbracelet/bubbletea"
 )
 
 // createTestModel creates a test model with sample data