initial commit: Artifacto v0.1

Self-hosted HTML artifact publisher. Single Go binary, SQLite metadata,
HTML on disk. Features: password-protected artifacts, per-artifact expiration,
admin dashboard with view metrics (privacy-preserving daily-salt visitor hash,
sparklines, 30-day SVG chart, top referrers), rate-limited unlock endpoint.

Packaged as a Docker image (two-stage, CGO_ENABLED=0, pure-Go SQLite).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/server/templates/login.html

@@ -0,0 +1,22 @@
+{{ define "login" }}
+{{ template "head" "Log in" }}
+{{ template "header" false }}
+<main class="max-w-6xl mx-auto px-6 py-8">
+  <div class="max-w-sm mx-auto mt-16">
+    <h1 class="text-2xl font-semibold mb-4">Log in</h1>
+    {{ if .Error }}
+      <div class="rounded bg-red-900/40 border border-red-800 text-red-200 px-3 py-2 mb-3 text-sm">{{ .Error }}</div>
+    {{ end }}
+    <form method="post" action="/login" class="space-y-3">
+      <input type="hidden" name="next" value="{{ .Next }}">
+      <label class="block">
+        <span class="block text-sm text-slate-400 mb-1">Password</span>
+        <input type="password" name="password" required autofocus autocomplete="current-password"
+               class="w-full bg-slate-900 border border-slate-800 rounded px-3 py-2 focus:outline-none focus:border-indigo-500">
+      </label>
+      <button class="w-full bg-indigo-600 hover:bg-indigo-500 text-white rounded px-3 py-2 font-medium">Log in</button>
+    </form>
+  </div>
+</main>
+{{ template "footer" }}
+{{ end }}