add experimental boot

web/boot/index.html

@@ -0,0 +1,56 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <title>Kiri:Moto (loading)</title>
+    <style>
+        body {
+            top: 0;
+            left: 0;
+            right: 0;
+            bottom: 0;
+            display: flex;
+            position: fixed;
+            align-items: center;
+            flex-direction: column;
+            justify-content: center;
+            font-family: sans-serif;
+            font-weight: bold;
+        }
+    </style>
+    <script>
+        (async () => {
+            const reg = await navigator.serviceWorker.register('/boot/service.js', { scope: '/' });
+            await reg.update();
+            await navigator.serviceWorker.ready;
+
+            if (!navigator.serviceWorker.controller) {
+                console.log('No controller → reloading under SW control');
+                location.reload();
+                return;
+            }
+
+            navigator.serviceWorker.controller.postMessage({
+                mode: 'cached',
+                version: 1
+            });
+
+            navigator.serviceWorker.addEventListener('message', e => {
+                if (e.data === 'preload-complete') {
+                    console.log('preload complete');
+                    location.replace('/kiri/index.html');
+                } else if (e.data === 'preload-cached') {
+                    console.log('preload cached');
+                    location.replace('/kiri/index.html');
+                }
+            });
+        })();
+    </script>
+</head>
+
+<body>
+    Kiri:Moto is Loading
+</body>
+
+</html>