Add DOCX export endpoint and Export button

- GET /api/export generates a Word document with all non-archived prayers
- Accepts ?status=active|answered|all and ?tag= query params to match
  the current filter/tag selection in the UI
- Document sections: Active Prayers + Answered Prayers with page break,
  each prayer showing person, request, answer, dates, and tags
- Styled with Palatino Linotype, page numbers in footer
- Export button in the toolbar triggers download of dated .docx file

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DReRqHxSYuVfCzTzQGD9hZ

src/App.tsx

@@ -103,6 +103,13 @@ export default function App() {
     setActiveTag(prev => prev === tag ? null : tag);
   }
 
+  function handleExport() {
+    const params = new URLSearchParams();
+    params.set('status', filter);
+    if (activeTag) params.set('tag', activeTag);
+    window.location.href = `/api/export?${params.toString()}`;
+  }
+
   const emptyMessage = search
     ? `No results for "${search}".`
     : activeTag
@@ -167,6 +174,10 @@ export default function App() {
           </button>
         </div>
 
+        <button className="btn btn-export" onClick={handleExport} title="Export to Word">
+          ↓ Export
+        </button>
+
         <div className="search-wrap">
           <span className="search-icon">⌕</span>
           <input