feat(ui): implement dark mode customer deliveries and activity center

[shepherd-001]

Summary

This PR implements the requested Figma dark-mode designs for customer delivery management and the Activity Center in the SwiftChain frontend.

Implemented

• Implemented Customer Active Deliveries — Table Views.
• Implemented Customer Active Deliveries — Grid Views.
• Implemented Customer Active Deliveries — List Views.
• Implemented the Activity Center Page for shipment updates and smart contract alerts.
• Updated the required routes for the new interfaces.
• Applied dark-mode color variables and appropriate contrast ratios.
• Implemented responsive layouts across desktop and mobile viewports.
• Matched the implemented layouts and component structures with the provided Figma designs.

Validation

• Tested the implemented interfaces locally.
• Verified responsive behavior across desktop and mobile viewports.
• Checked dark-mode colors, contrast, spacing, typography, and component consistency.
• Verified that the changes do not introduce visual or functional regressions.

Issues

Closes #451
Closes #452
Closes #453
Closes #454