book: single export button (Save as PDF / Print, always current); drop the pre-rendered snapshot PDF

app.js

@@ -592,8 +592,8 @@ function toggleTreeCat(cat) {
 
 /* ── BOOK VIEW (#/book) — the whole wiki as one printable document ─────────
    Browser "Save as PDF" (or the pre-rendered download) turns this into a book:
-   title page → contents → parts (categories) → articles → sources appendix. */
-const BOOK_PDF_URL = 'rl-llm-wiki-book.pdf';   // pre-rendered snapshot hosted alongside the app
+   title page → contents → parts (categories) → articles → sources appendix.
+   The single export path is the browser's "Save as PDF" (always current). */
 async function renderBook() {
   layoutAside(false);
   setView('<div class="loading"><div class="spinner"></div><span id="bkProg">assembling the book…</span></div>');
@@ -652,8 +652,7 @@ async function renderBook() {
     <div class="book-toolbar" role="toolbar">
       <a class="btn" href="#/">← back to the wiki</a>
       <span class="spacer"></span>
-      <span class="bk-hint">Tip: “Save as PDF” in the print dialog for the full book.</span>
-      <a class="btn" href="${esc(BOOK_PDF_URL)}" target="_blank" rel="noopener" id="bkDownload">download PDF ↓</a>
+      <span class="bk-hint">Choose “Save as PDF” in the print dialog for the full book.</span>
       <button class="btn btn-sources" id="bkPrint">Save as PDF / Print</button>
     </div>
     <div class="book" id="book">

rl-llm-wiki-book.pdf

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:b7e68748637a27a58e3299855cdfe0481c91a2c3f769a372ffb4a35fb0b1141f
-size 5074238