fix: upload failure, share dialog, shared view styling, dark mode fixes

- Fix 'folder_id is required' upload error by adding create_home_folder
  through the full hexagonal architecture (trait, service, repository, auth)
- Fix double upload issue with _isUploading concurrency guard
- Fix Share context menu doing nothing (ID collision between sharedView
  and main share dialog resolved with sv- prefix)
- Fix Compartidos tab duplicate headers and broken layout
- Add missing .shared-dialog CSS with dark mode support
- Fix dark mode white backgrounds on empty-state, shared-filters,
  trash-actions, action-btn, and header
- Fix i18n key mismatches in sharedView
- Bump version to 0.4.1

Closes #120

src/application/services/folder_service.rs

@@ -111,6 +111,10 @@ impl FolderService {
             async fn delete_folder(&self, _id: &str, _caller_id: &str) -> Result<(), DomainError> {
                 Ok(())
             }
+
+            async fn create_home_folder(&self, _user_id: &str, _name: String) -> Result<FolderDto, DomainError> {
+                Ok(FolderDto::empty())
+            }
         }
 
         FolderServiceStub
@@ -154,6 +158,22 @@ impl FolderUseCase for FolderService {
         Ok(FolderDto::from(folder))
     }
 
+    /// Creates a root-level home folder for a user during registration.
+    async fn create_home_folder(&self, user_id: &str, name: String) -> Result<FolderDto, DomainError> {
+        let folder = self
+            .folder_storage
+            .create_home_folder(user_id, name)
+            .await
+            .map_err(|e| {
+                DomainError::internal_error(
+                    "FolderStorage",
+                    format!("Failed to create home folder: {}", e),
+                )
+            })?;
+
+        Ok(FolderDto::from(folder))
+    }
+
     /// Gets a folder by its ID
     async fn get_folder(&self, id: &str) -> Result<FolderDto, DomainError> {
         let folder = self.folder_storage.get_folder(id).await.map_err(|e| {