Introduce tree view and dependency policy visibility in Dependency Firewall

🔥 Problem

Users can’t easily understand the relationship between a top-level package and its transitive dependencies, or which dependencies are being blocked or allowed by policy. The current flat dependency list doesn't convey hierarchy, making it harder to trace vulnerabilities or policy enforcement across nested dependencies.

💡 Proposal

• Introduce a tree view to visualise parent-child relationships between dependencies (direct and transitive).
• Surface policy visibility and vulnerability status next to each dependency (e.g., allowed, blocked, pending review), giving users immediate context on enforcement results.
• This will help users quickly trace risk sources and compliance decisions within their dependency graph.