refactor: move internal/ to pkg/ for external importability

Moves all packages from internal/ to pkg/ so they can be imported
by external modules (needed for claude-pm integration).

- internal/app/ → pkg/app/
- internal/docker/ → pkg/docker/
- internal/config/ → pkg/config/
- internal/utils/ → pkg/utils/

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/utils/table.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"strings"
+
+	"github.com/olekukonko/tablewriter"
+)
+
+func FormatTable(data [][]string) string {
+	var sb strings.Builder
+	table := tablewriter.NewWriter(&sb)
+	table.SetHeader([]string{})
+	table.SetBorder(false)
+	table.SetColMinWidth(0, 10)
+	table.SetColMinWidth(1, 20)
+	table.SetColMinWidth(2, 25)
+	table.SetColMinWidth(3, 15)
+	table.SetColMinWidth(4, 20)
+
+	for _, row := range data {
+		table.Append(row)
+	}
+
+	table.Render()
+	return sb.String()
+}