feat(ui): add PDF export via browser print

Adds a PDF button to the report header. Clicking it opens
/chart/current?print=true in a new tab, which auto-triggers
window.print() so the user can save to PDF via the browser dialog.

- chart submodule bumped: PrintMode support (no filter JS, auto-print,
  @media print CSS)
- handlers.go: passes PrintMode=true when ?print=true query param is set
- index.html: PDF button alongside Raw Data / Reanimator
- app.js: printReport() helper; button shown/hidden with other exports

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible-local/07-exporters.md

@@ -7,6 +7,7 @@
 | `GET /api/export/csv` | CSV | Serial-number export |
 | `GET /api/export/json` | raw-export ZIP bundle | Reopen and re-analyze later |
 | `GET /api/export/reanimator` | JSON | Reanimator hardware payload |
+| `GET /chart/current?print=true` | HTML (auto-print) | Print/PDF version of the report — opens in new tab, calls `window.print()` |
 | `POST /api/convert` | async ZIP artifact | Batch archive-to-Reanimator conversion |
 
 ## Raw export

internal/server/handlers.go

@@ -84,7 +84,10 @@ func (s *Server) handleChartCurrent(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	html, err := chartviewer.RenderHTML(snapshotBytes, title)
+	printMode := r.URL.Query().Get("print") == "true"
+	html, err := chartviewer.RenderHTMLWithOptions(snapshotBytes, title, chartviewer.RenderOptions{
+		PrintMode: printMode,
+	})
 	if err != nil {
 		http.Error(w, "failed to render chart: "+err.Error(), http.StatusInternalServerError)
 		return

web/static/js/app.js

@@ -1410,6 +1410,7 @@ async function loadData(vendor, filename) {
     document.getElementById('clear-btn').classList.remove('hidden');
     document.getElementById('header-raw-btn').classList.remove('hidden');
     document.getElementById('header-reanimator-btn').classList.remove('hidden');
+    document.getElementById('header-pdf-btn').classList.remove('hidden');
     document.getElementById('header-log-meta').classList.remove('hidden');
 
     loadAuditViewer();
@@ -1509,6 +1510,10 @@ function exportData(format) {
     window.location.href = `/api/export/${format}`;
 }
 
+function printReport() {
+    window.open('/chart/current?print=true', '_blank');
+}
+
 // Clear data
 async function clearData() {
     try {
@@ -1518,6 +1523,7 @@ async function clearData() {
         document.getElementById('clear-btn').classList.add('hidden');
         document.getElementById('header-raw-btn').classList.add('hidden');
         document.getElementById('header-reanimator-btn').classList.add('hidden');
+        document.getElementById('header-pdf-btn').classList.add('hidden');
         document.getElementById('header-log-meta').classList.add('hidden');
         document.getElementById('upload-status').textContent = '';
         const frame = document.getElementById('audit-viewer-frame');

web/templates/index.html

@@ -18,6 +18,7 @@
                 <button id="clear-btn" class="header-action hidden" onclick="clearData()">Clear Data</button>
                 <button id="header-raw-btn" class="header-action hidden" onclick="exportData('json')">Raw Data</button>
                 <button id="header-reanimator-btn" class="header-action hidden" onclick="exportData('reanimator')">Reanimator</button>
+                <button id="header-pdf-btn" class="header-action hidden" onclick="printReport()">PDF</button>
                 <button id="restart-btn" class="header-action" onclick="restartApp()">Restart</button>
                 <button id="exit-btn" class="header-action" onclick="exitApp()">Exit</button>
             </div>