This commit adds explicit type annotations to variables, function parameters, and return types throughout the codebase, particularly in widget trees, Bloc logic, and repository implementations. The changes improve code readability, maintainability, and type safety, and align with Dart best practices. No business logic was changed.
Relocated all app directories (client, design_system_viewer, staff) and their contents under the new 'apps/mobile' path. This change improves project organization and prepares for future platform-specific structuring.
