fix: TOC PDF - forcer le rechargement de l'iframe (BUG-063 complement)

frontend/js/viewer.js

@@ -521,10 +521,12 @@ function applyPrettyHighlight(codeEl, lang, text) {
 /**
  * Jump the inline PDF viewer to a specific page.
  *
- * The browser's built-in PDF viewer lives in an ``about:blank`` content window,
- * so assigning ``contentWindow.location.hash`` never reaches the document (the
- * TOC links used to do exactly that and did nothing). Reloading the iframe with
- * the ``#page=N`` fragment is the supported way to target a page.
+ * The browser's built-in PDF viewer lives in an ``about:blank`` content window
+ * (so ``contentWindow.location.hash`` never reaches the document) **and** it
+ * ignores a same-document fragment navigation: changing only ``#page=N`` on the
+ * iframe ``src`` does not move the page. A changing query parameter forces a
+ * real reload, and the ``#page=N`` fragment is then honoured at load — the only
+ * reliable way to target a page with the native viewer.
  *
  * @param {HTMLElement} area - Content area containing the ``.pdf-iframe``.
  * @param {string|number} page - 1-based page number from the PDF outline.
@@ -534,7 +536,8 @@ export function navigatePdfToPage(area, page) {
   if (!iframe || page === null || page === undefined || page === '') return;
   const base = iframe.getAttribute('data-pdf-url') || iframe.src.split('#')[0];
   iframe.setAttribute('data-pdf-url', base);
-  iframe.src = `${base}#page=${page}`;
+  const sep = base.includes('?') ? '&' : '?';
+  iframe.src = `${base}${sep}_pdfpage=${Date.now()}#page=${page}`;
 }
 
 export function renderFile(data) {