fix: reset chapter navigation to article top

Author: ryosukeeeeee

docs/index.html

@@ -119,7 +119,7 @@
     </noscript>
 
     <script src="./vendor/gitalk.min.js"></script>
-    <script src="./scripts/site.js?v=20260716-11"></script>
+    <script src="./scripts/site.js?v=20260716-12"></script>
     <script src="./vendor/docsify.min.js"></script>
     <script src="./vendor/prism-bash.min.js"></script>
     <script src="./vendor/search.min.js"></script>

docs/scripts/site.js

@@ -312,7 +312,6 @@
     notFoundPage: true,
     subMaxLevel: 3,
     maxLevel: 4,
-    topMargin: 88,
     externalLinkTarget: "_blank",
     externalLinkRel: "noopener noreferrer",
     search: {

scripts/validate-site.mjs

@@ -33,6 +33,7 @@ assert(siteScript.includes('new URL("last-updated.json", document.baseURI)'), "L
 assert(!siteScript.includes("api.github.com/repos/"), "Last-updated dates must not depend on the GitHub API at runtime.");
 assert(siteScript.includes('"/.*/_sidebar.md": "/_sidebar.md"'), "Nested routes must reuse the root sidebar.");
 assert(!siteScript.includes("formatUpdated:"), "Unused Docsify update formatting must stay removed.");
+assert(!siteScript.includes("topMargin:"), "Deprecated topMargin must not offset chapter navigation.");
 assert(workflow.includes("fetch-depth: 0"), "The deployment checkout must include full Git history.");
 assert(packageSource.includes("scripts/generate-last-updated.mjs"), "The local preview does not generate last-updated metadata.");