feat: Add version command line argument

lib/tetra/ui/main.rb

@@ -3,6 +3,11 @@
 module Tetra
   # program entry point
   class MainCommand < Clamp::Command
+    option ["-v", "--version"], :flag, "print the version and exit" do
+      puts Tetra::VERSION
+      exit(0)
+    end
+
     subcommand(
       "init",
       "Inits a tetra project in the current directory",

spec/lib/coarse/version_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe "tetra version flag", type: :aruba do
+  it "prints the version with --version" do
+    # Run the command
+    run_command_and_stop("tetra --version")
+
+    # Verify the exit status is 0 (success)
+    expect(last_command_started).to be_successfully_executed
+
+    # Verify the output matches the Ruby constant
+    expect(last_command_started).to have_output(Tetra::VERSION)
+  end
+
+  it "prints the version with -v" do
+    run_command_and_stop("tetra -v")
+
+    expect(last_command_started).to be_successfully_executed
+    expect(last_command_started).to have_output(Tetra::VERSION)
+  end
+end