feat: add Hetzner-hosted todo application stack

Implement the server-rendered Go todo application with PostgreSQL persistence, Tailwind styling, health checks, and test coverage.

Provision production and staging infrastructure with OpenTofu, including private networking, static IPs, Object Storage backups, and load balancing.

Configure Rocky Linux hosts with Ansible, rootless Podman, PostgreSQL, WAL-G backup automation, staging restores, and generated inventory.

app/web/templates/layouts/base.html

@@ -0,0 +1,16 @@
+{{define "layout"}}
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width,initial-scale=1">
+  <title>Field Notes</title>
+  <link rel="stylesheet" href="/static/app.css">
+</head>
+<body class="min-h-screen bg-stone-950 text-stone-100 antialiased">
+  <main class="mx-auto max-w-3xl px-5 py-12 sm:px-8 sm:py-20">
+    {{template "content" .}}
+  </main>
+</body>
+</html>
+{{end}}