Build relationship explorer UI component

[joshuapare]

Context

Once GraphService is bound to Wails, the frontend needs a component to display relationships for a selected resource. The backend supports three query types: direct relationships, relationship chains (BFS by type), and full dependency trees.

What to do

1. Create a relationship panel/drawer that shows edges for a selected resource
2. Use GetRelated() for the default view — show incoming and outgoing edges grouped by relationship type
3. Each edge should link to the target resource (clicking navigates to it)
4. Support filtering by relationship type (owns, uses, runs_on, selects, manages)
5. Consider a tree view using GetDependencyTree() for visualizing ownership hierarchies

Depends on

• GraphService Wails binding issue (must be merged first)

Design notes

• Start simple: a sidebar panel or tab on the resource detail view
• Group edges by type with counts
• Show target resource kind + name + namespace