refactor(download): rename locationStep id to downloadLocationStep

The download modal's step shared the 'locationStep' id with the import
modal, so getElementById('locationStep') could resolve to the wrong
element depending on template include order. The import flow relied on
an injected display:block !important rule to work around it.

Rename the download modal's step id and update all references so each
modal owns a unique step id.

static/css/components/import-modal.css

@@ -1,4 +1,35 @@
 /* Import Modal Styles */
+
+/* Sticky footer layout: fixed header, scrollable step content, pinned action buttons.
+   Ensures Back/Import buttons stay visible on short viewports (e.g. 1080p or 150% zoom). */
+#importModal .modal-content {
+    display: flex;
+    flex-direction: column;
+    overflow: hidden; /* The active step scrolls instead of the whole modal */
+}
+
+#importModal .modal-header {
+    flex-shrink: 0;
+}
+
+#importModal .import-step {
+    flex: 1 1 auto;
+    min-height: 0; /* Allow the step to shrink and scroll within the flex container */
+    overflow-y: auto;
+    overflow-x: hidden;
+    scrollbar-gutter: stable;
+}
+
+#importModal .import-step .modal-actions {
+    position: sticky;
+    bottom: 0;
+    z-index: 1;
+    background: var(--lora-surface);
+    border-top: 1px solid var(--lora-border);
+    padding-top: var(--space-2);
+    padding-bottom: var(--space-1);
+}
+
 .import-step {
     margin: var(--space-2) 0;
     transition: none !important;

static/js/managers/DownloadManager.js

@@ -754,7 +754,7 @@ export class DownloadManager {
             this.selectedFile?.id, this.selectedFile?.name, this.selectedFile?.type, this.selectedFile?.metadata);
 
         document.getElementById('fileSelectionStep').style.display = 'none';
-        document.getElementById('locationStep').style.display = 'block';
+        document.getElementById('downloadLocationStep').style.display = 'block';
         this.proceedToLocationContent();
     }
 
@@ -788,7 +788,7 @@ export class DownloadManager {
         }
 
         document.querySelectorAll('.download-step').forEach(step => step.style.display = 'none');
-        document.getElementById('locationStep').style.display = 'block';
+        document.getElementById('downloadLocationStep').style.display = 'block';
         await this.proceedToLocationContent();
     }
 
@@ -1563,7 +1563,7 @@ export class DownloadManager {
     }
 
     backToVersions() {
-        document.getElementById('locationStep').style.display = 'none';
+        document.getElementById('downloadLocationStep').style.display = 'none';
         if (this.isBatchMode) {
             document.getElementById('batchPreviewStep').style.display = 'block';
         } else {

static/js/managers/import/ImportStepManager.js

@@ -47,11 +47,8 @@ export class ImportStepManager {
                 targetStep.offsetHeight;
             }
             
-            // Scroll modal content to top
-            const modalContent = document.querySelector('#importModal .modal-content');
-            if (modalContent) {
-                modalContent.scrollTop = 0;
-            }
+            // Scroll the active step back to top (steps scroll independently of the modal shell)
+            targetStep.scrollTop = 0;
         }
     }
 }

templates/components/modals/download_modal.html

@@ -60,7 +60,7 @@
         </div>
 
         <!-- Step 3: Location Selection -->
-        <div class="download-step" id="locationStep" style="display: none;">
+        <div class="download-step" id="downloadLocationStep" style="display: none;">
             <div class="location-selection">
                 <!-- Path preview with inline toggle -->
                 <div class="path-preview">

tests/frontend/managers/downloadManager.latestVersion.test.js

@@ -118,7 +118,7 @@ function setupDownloadDom() {
       <div class="download-step" id="urlStep"></div>
       <div class="download-step" id="versionStep"></div>
       <div class="download-step" id="fileSelectionStep"></div>
-      <div class="download-step" id="locationStep"></div>
+      <div class="download-step" id="downloadLocationStep"></div>
       <div id="batchPreviewStep"></div>
       <textarea id="modelUrl"></textarea>
       <div id="urlError"></div>