[Task] (Heureka): Implement risk acceptance action, modal, and vulnerability state update between tabs

[hodanoori]

Acceptance Criteria

• A Risk Acceptance action is available for eligible vulnerabilities.
• Selecting the action opens a Risk Acceptance modal with required inputs.
• Submitting the modal successfully records the risk acceptance.
• The vulnerability state is updated accordingly and reflected between the Active and Vulnerabilities tabs.
• UI updates immediately after submission without page reload.