changes to series order system. add artist retagging tool

app/templates/_gallery_modal.html

@@ -12,6 +12,7 @@
       </div>
 
       <div id="modalTagEditor" class="tag-editor" data-image-id="">
+        <!-- Shown when image IS in a series -->
         <div id="modalSeriesInfo" class="modal-series-info" style="display: none;">
           <div class="series-info-row">
             <span class="series-info-label">📚 Page</span>
@@ -22,6 +23,20 @@
             <span id="pageUpdateStatus" class="page-update-status"></span>
           </div>
         </div>
+        <!-- Shown when image is NOT in a series -->
+        <div id="modalAddToSeries" class="modal-add-to-series" style="display: none;">
+          <div class="add-series-header">
+            <span class="series-info-label">📚 Add to Series</span>
+          </div>
+          <div class="add-series-controls">
+            <select id="seriesSelect" class="series-select">
+              <option value="">Select series...</option>
+            </select>
+            <input type="number" id="addSeriesPageNumber" min="1" value="1" class="series-page-input" placeholder="#">
+            <button id="addToSeriesBtn" class="btn-small" disabled>Add</button>
+          </div>
+          <span id="addToSeriesStatus" class="page-update-status"></span>
+        </div>
         <div id="modalTagList" class="tags"></div>
         <form id="modalTagForm" class="tag-form" autocomplete="off">
           <div class="tag-form-wrapper">