Phase 1: Control Service skeleton (Go, SQLite, session login, Docker, Caddy)

- Go service with its own multi-stage Dockerfile and docker-compose.yml; runs
  as container webrestrict-control on port 8791.
- SQLite schema for the full AGENTS.md §7 data model via versioned migrations
  (PRAGMA user_version); audit log is append-only.
- Configuration from the process environment; the real env file is gitignored
  and a template is committed. No secrets in the repo.
- Separate session login (signed HMAC cookie + CSRF) for Sam.
- GET /health; HTMX + server-rendered dashboard styled with the Family Home Lab
  tokens.css (copied) and Inter fonts; dark mode; phone-friendly.
- Caddy vhost for webrestrict.lab.audasmedia.com.au applied on .35 (Let's
  Encrypt cert issued); route recorded in deploy/caddy/webrestrict.caddy.
- Unit tests for config, auth and store.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

internal/web/templates/login.html

@@ -0,0 +1,40 @@
+{{define "login.html"}}<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <meta name="color-scheme" content="light dark">
+  <title>Sign in — Internet Use Control</title>
+  <link rel="stylesheet" href="/static/tokens.css">
+  <link rel="stylesheet" href="/static/app.css">
+</head>
+<body class="login-page">
+  <main class="login-band">
+    <div class="login-band__inner">
+      <p class="login-eyebrow">Internet Use Control</p>
+      <h1 class="login-headline">Good to see you,<br>Sam.</h1>
+      <p class="login-sub">Sign in to manage the kids' devices.</p>
+    </div>
+
+    <section class="auth-card" aria-labelledby="signin-title">
+      <h2 id="signin-title" class="auth-card__title">Sign in</h2>
+      {{if .Error}}<p class="auth-error" role="alert">{{.Error}}</p>{{end}}
+      <form method="post" action="/login" class="auth-form" autocomplete="on">
+        <input type="hidden" name="csrf" value="{{.CSRF}}">
+        <label class="field">
+          <span class="field__label">Username</span>
+          <input class="text-input" type="text" name="username" value="{{.Username}}"
+                 autocomplete="username" autocapitalize="none" spellcheck="false" required>
+        </label>
+        <label class="field">
+          <span class="field__label">Password</span>
+          <input class="text-input" type="password" name="password"
+                 autocomplete="current-password" required>
+        </label>
+        <button class="button-primary" type="submit">Sign in</button>
+      </form>
+    </section>
+  </main>
+  <footer class="login-foot">Family Home Lab · Control Service</footer>
+</body>
+</html>{{end}}