feat(render-mode): Rich (LibreOffice) vs Standard (pandoc) toggle for office formats (.docx/.odt/.rtf); Rich default; 5 office tests; 152/152 green"

templates/index.html

@@ -346,6 +346,10 @@
         <h1>Drop a file to set it in type</h1>
         <p class="drop-note">or <span class="browse">browse your files</span> &middot; up to <span id="maxmb">400</span>&nbsp;MB &middot; <code>.epub .docx .odt .md .html .txt .csv .svg .png .pdf</code></p>
         <p id="droperr" class="drop-err" role="alert"></p>
+         <div class="render-modes" role="radiogroup" aria-label="Rendering mode">
+           <label class="mode-label"><input type="radio" name="render_mode" value="rich" checked> <span class="mode-name">Rich</span> &mdash; best fidelity (LibreOffice)</label>
+           <label class="mode-label"><input type="radio" name="render_mode" value="standard"> <span class="mode-name">Standard</span> &mdash; fastest (pandoc)</label>
+         </div>
         <input type="file" id="file" accept=".epub,.html,.htm,.txt,.log,.md,.markdown,.csv,.tsv,.json,.xml,.svg,.png,.jpg,.jpeg,.webp,.tiff,.bmp,.pdf,.docx,.odt,.rtf,.tex,.latex,.org,.adoc,.rst">
       </section>
 
@@ -456,6 +460,11 @@
     if (!OKEXT.test(f.name)) { flashError('Unsupported file type &mdash; accepted: .epub .html .htm .txt .log .md .markdown .csv .tsv .json .xml .svg .png .jpg .jpeg .webp .tiff .bmp .pdf .docx .odt .rtf .tex .latex .org .adoc .rst'); return; }
     var form = new FormData();
     form.append('file', f);
+     var modeEl = document.querySelector('input[name="render_mode"]:checked');
+     if (modeEl) form.append('render_mode', modeEl.value);
+     // AC: render_mode defaults to "rich" on the server when omitted; the UI
+     // always sends it (Rich preselected) so the choice reaches the worker.
+     // OKEXT (all 27 extensions) left unchanged — the toggle only gates office routing.
     showStatus();
     bookname.textContent = f.name;
     stateEl.textContent = 'Sending to the press';