refactor: remove Attach button from note editor header

- Remove confusing attachment upload button from header
- Simplify UI by keeping only category selector and preview toggle
- Attachment functionality removed from this section

src/components/NoteEditor.tsx

@@ -616,42 +616,6 @@ export function NoteEditor({ note, onUpdateNote, onUnsavedChanges, categories, i
               </svg>
             </div>
 
-            {/* Attachment Upload */}
-            <input
-              ref={fileInputRef}
-              type="file"
-              onChange={handleAttachmentUpload}
-              className="hidden"
-              accept="image/*,.pdf,.doc,.docx,.txt,.md"
-            />
-            <button
-              onClick={() => fileInputRef.current?.click()}
-              disabled={isUploading || isPreviewMode}
-              className={`px-3 py-1.5 rounded-full transition-colors flex items-center gap-1.5 text-sm ${
-                isUploading || isPreviewMode
-                  ? 'bg-gray-100 dark:bg-gray-700 text-gray-400 dark:text-gray-500 cursor-not-allowed'
-                  : 'bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-300 hover:bg-gray-200 dark:hover:bg-gray-600'
-              }`}
-              title={isPreviewMode ? "Switch to Edit mode to upload" : "Upload Image/Attachment"}
-            >
-              {isUploading ? (
-                <>
-                  <svg className="w-4 h-4 animate-spin" fill="none" viewBox="0 0 24 24">
-                    <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4"></circle>
-                    <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
-                  </svg>
-                  <span>Uploading...</span>
-                </>
-              ) : (
-                <>
-                  <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 16l4.586-4.586a2 2 0 012.828 0L16 16m-2-2l1.586-1.586a2 2 0 012.828 0L20 14m-6-6h.01M6 20h12a2 2 0 002-2V6a2 2 0 00-2-2H6a2 2 0 00-2 2v12a2 2 0 002 2z" />
-                  </svg>
-                  <span>Attach</span>
-                </>
-              )}
-            </button>
-
             {/* Preview Toggle */}
             <button
               onClick={() => setIsPreviewMode(!isPreviewMode)}