LCFS - E2E Coverage for Admin, Dashboard, and Notifications

[AlexZorkin]

Description
Add Cypress E2E coverage for Admin and operational views that currently have no tests.

Purpose
Reduce high-risk gaps in admin workflows and system operations.

Acceptance Criteria

• Cypress specs exist for: Admin, Dashboard, Notifications.
• Happy-path flows for each view are covered end-to-end.
• Tests run green alongside the existing suite.

Additional context

• These views are present under frontend/src/views but have no matching E2E coverage today.