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/ports/inbound.rs

@@ -55,6 +55,9 @@ pub trait FolderUseCase: Send + Sync + 'static {
 
     /// Deletes a folder (ownership verified against caller_id)
     async fn delete_folder(&self, id: &str, caller_id: &str) -> Result<(), DomainError>;
+
+    /// 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>;
 }
 
 /**