refactor(docs): migrate documentation to Blume and restructure content

docs/worker.js

@@ -0,0 +1,28 @@
+export default {
+  async fetch(request, env) {
+    const auth = request.headers.get("Authorization") ?? "";
+    if (auth.startsWith("Basic ")) {
+      let ok = false;
+      try {
+        const decoded = atob(auth.slice(6));
+        const password = decoded.slice(decoded.indexOf(":") + 1); // password may contain ':'
+        ok = await passwordMatches(password, env.SITE_PASSWORD);
+      } catch {}
+      if (ok) return env.ASSETS.fetch(request);
+    }
+    return new Response("Authentication required", {
+      status: 401,
+      headers: { "WWW-Authenticate": 'Basic realm="leetcode-docs", charset="UTF-8"' },
+    });
+  },
+};
+
+// timingSafeEqual needs equal-length buffers → hash both sides first
+async function passwordMatches(candidate, expected) {
+  const enc = new TextEncoder();
+  const [a, b] = await Promise.all([
+    crypto.subtle.digest("SHA-256", enc.encode(candidate)),
+    crypto.subtle.digest("SHA-256", enc.encode(expected)),
+  ]);
+  return crypto.subtle.timingSafeEqual(a, b);
+}