feat: Enhance WebDAV file management and UI

- Add functionality to create new collections via API
- Implement copy and move operations between collections
- Improve image rendering in markdown preview with relative path resolution
- Add support for previewing binary files (images, PDFs)
- Refactor modal styling to use flat buttons and improve accessibility

static/js/collection-selector.js

@@ -26,12 +26,21 @@ class CollectionSelector {
                 this.select.appendChild(option);
             });
 
-            // Try to restore previously selected collection from localStorage
-            const savedCollection = localStorage.getItem(this.storageKey);
+            // Determine which collection to select (priority: URL > localStorage > first)
             let collectionToSelect = collections[0]; // Default to first
 
-            if (savedCollection && collections.includes(savedCollection)) {
-                collectionToSelect = savedCollection;
+            // Check URL first (highest priority)
+            const urlCollection = this.getCollectionFromURL();
+            if (urlCollection && collections.includes(urlCollection)) {
+                collectionToSelect = urlCollection;
+                Logger.info(`Using collection from URL: ${urlCollection}`);
+            } else {
+                // Fall back to localStorage
+                const savedCollection = localStorage.getItem(this.storageKey);
+                if (savedCollection && collections.includes(savedCollection)) {
+                    collectionToSelect = savedCollection;
+                    Logger.info(`Using collection from localStorage: ${savedCollection}`);
+                }
             }
 
             if (collections.length > 0) {
@@ -48,14 +57,17 @@ class CollectionSelector {
                 // Save to localStorage
                 localStorage.setItem(this.storageKey, collection);
                 this.webdavClient.setCollection(collection);
-                
+
                 Logger.info(`Collection changed to: ${collection}`);
-                
+
+                // Update URL to reflect collection change
+                this.updateURLForCollection(collection);
+
                 if (this.onChange) {
                     this.onChange(collection);
                 }
             });
-            
+
             Logger.debug(`Loaded ${collections.length} collections`);
         } catch (error) {
             Logger.error('Failed to load collections:', error);
@@ -83,9 +95,12 @@ class CollectionSelector {
             this.select.value = collection;
             localStorage.setItem(this.storageKey, collection);
             this.webdavClient.setCollection(collection);
-            
+
             Logger.info(`Collection set to: ${collection}`);
-            
+
+            // Update URL to reflect collection change
+            this.updateURLForCollection(collection);
+
             if (this.onChange) {
                 this.onChange(collection);
             }
@@ -93,6 +108,43 @@ class CollectionSelector {
             Logger.warn(`Collection "${collection}" not found in available collections`);
         }
     }
+
+    /**
+     * Update the browser URL to reflect the current collection
+     * @param {string} collection - The collection name
+     */
+    updateURLForCollection(collection) {
+        // Get current URL parameters
+        const urlParams = new URLSearchParams(window.location.search);
+        const isEditMode = urlParams.get('edit') === 'true';
+
+        // Build new URL with collection
+        let url = `/${collection}/`;
+        if (isEditMode) {
+            url += '?edit=true';
+        }
+
+        // Use pushState to update URL without reloading
+        window.history.pushState({ collection, filePath: null }, '', url);
+        Logger.debug(`Updated URL to: ${url}`);
+    }
+
+    /**
+     * Extract collection name from current URL
+     * URL format: /<collection>/ or /<collection>/<file_path>
+     * @returns {string|null} The collection name or null if not found
+     */
+    getCollectionFromURL() {
+        const pathname = window.location.pathname;
+        const parts = pathname.split('/').filter(p => p); // Remove empty parts
+
+        if (parts.length === 0) {
+            return null;
+        }
+
+        // First part is the collection
+        return parts[0];
+    }
 }
 
 // Make CollectionSelector globally available