feat: Add CLI application entry point with main function delegating to internal app package

- Add main.go with main function calling app.Main() from internal/app package
- Import telecom-platform CLI app package for application initialization

apps/cli/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"github.com/nutcas3/telecom-platform/apps/cli/internal/app"
+)
+
+func main() {
+	app.Main()
+}