chore: add project scaffolding and build tooling

Go module, makefile (build, test, docker, e2e targets), version embedding, initialize script, vars template, ignores and the project plan.

initialize.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2026 Bryan Joshua Pedini
+
+set -euo pipefail
+
+if [ ! -f ".vars" ]; then
+  cp vars.example .vars
+fi
+
+if [ ! -f "go.mod" ]; then
+  module_name=$(git remote get-url origin | sed 's|^https://||')
+  go mod init "$module_name"
+fi