Add clickable links for node types and edge types in schema explorer details panel

[1wos]

Closes #1542.

Summary

Makes the vertex types and edge type rendered in EdgeConnectionRow clickable. Clicking a vertex type or edge type updates the schema graph selection to that item, keeping both the sidebar details and the graph view highlight in sync.

Changes

• Details.tsx
  • VertexTypeText and EdgeTypeText accept an optional onClick prop. When provided, they render as <button type="button"> with focus-visible styles for keyboard support; otherwise they remain <span>s with no behavior change.
  • EdgeConnectionRow accepts an optional onSelectionChange: (item: SchemaGraphSelectionItem) => void. When provided, it builds click handlers for the source vertex, edge type, and target vertex that invoke onSelectionChange with the appropriate selection item (using createEdgeConnectionId for the edge case).
• NodeLabelDetails.tsx, EdgeConnectionDetails.tsx
  • Accept and forward the optional onSelectionChange to EdgeConnectionRow.
• SchemaDetailsContent.tsx, SchemaExplorerSidebar.tsx
  • Accept and forward the optional onSelectionChange down the tree.
• SchemaGraph.tsx
  • New handleSidebarSelectionChange that updates both selection (SchemaGraphSelection) and graphSelection (SelectedElements), keeping the graph view highlight in sync as required by the issue.

Behavior notes

• Backwards compatible: onSelectionChange is optional everywhere it is threaded. Components rendered without it behave exactly as before (no buttons, no behavior change).
• a11y: clickable types are real <button> elements with focus-visible:ring, working with keyboard (Tab / Enter / Space) and screen readers.
• Visual styling is unchanged; hover (hover:text-text-primary) and focus rings are added on top of the existing underline/italic styles.
• Naming: chose onSelectionChange (matching the example in the issue's implementation notes) instead of onSelect to avoid clashing with the React onSelect event handler that components extending ComponentPropsWithRef<typeof Panel> already inherit.

Tests

Added five behavior tests in Details.test.tsx:

1. EdgeConnectionRow without onSelectionChange renders no buttons (back-compat).
2. With onSelectionChange, renders three buttons (source vertex / edge type / target vertex).
3. Clicking the source vertex calls onSelectionChange with { type: "vertex-type", id: <source> }.
4. Clicking the target vertex calls onSelectionChange with { type: "vertex-type", id: <target> }.
5. Clicking the edge calls onSelectionChange with { type: "edge-connection", id: <edgeConnectionId> }.

Verification

• pnpm exec vitest run packages/graph-explorer/src/modules/SchemaGraph/Sidebar/Details.test.tsx — 8/8 passing.
• pnpm exec tsc --noEmit (in packages/graph-explorer) — clean.
• pnpm exec eslint packages/graph-explorer/src/modules/SchemaGraph/ — clean.
• pnpm exec prettier --check on the seven changed files — clean.