Improve performance on poor connections: local assets, gzip, caching

- Replace Tailwind CDN (~350KB) with purged local CSS (~22KB)
- Replace htmx unpkg CDN with local static file
- Add Gzip middleware (standard library, sync.Pool) for all responses
- Add Cache-Control: public, max-age=3600 for /static/* assets
- Reduce status polling interval from 5s to 30s
- Add scripts/build-css.sh for CSS regeneration after template changes
- Document in bible-local/operations.md and history.md

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/templates/base.html

@@ -5,8 +5,9 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>{{template "title" .}}</title>
-    <script src="https://cdn.tailwindcss.com"></script>
-    <script src="https://unpkg.com/htmx.org@1.9.10"></script>
+    <link rel="stylesheet" href="/static/tailwind.min.css">
+    <link rel="stylesheet" href="/static/app.css">
+    <script src="/static/js/htmx.min.js"></script>
     <style>
         .htmx-request { opacity: 0.5; }
         .line-clamp-2 { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
@@ -163,7 +164,7 @@
 
         document.addEventListener('DOMContentLoaded', function () {
             refreshSystemStatus();
-            setInterval(refreshSystemStatus, 5000); // 5 second polling
+            setInterval(refreshSystemStatus, 30000); // 30 second polling
         });
     </script>
 </body>