kg: ExploreGraph.test.ts — 3 tests skipped pending Vue 3.5 hoisting workaround #694

Follow-up from PR #687 (Track 3-B).

Context

Three tests in app/explore/src/__tests__/ExploreGraph.test.ts are .skip'd because they assert on mockSigmaInstances[0] / mockGraphInstances[0], which are populated only when ExploreGraph's onMounted hook actually instantiates Sigma + Graph.

Under Vue 3.5.34 + @vue/test-utils 2.4.10 + happy-dom 15, the container template-ref resolves to null at onMounted time because Vue's SFC compiler hoists the static <div ref="container"> vnode and refs can't be attached to hoisted vnodes. The :data-graph-id workaround that defeats hoisting on other components doesn't trip the inner ref binding here.

Skipped tests

• deduplicates duplicate edges by key
• emits nodeClick when Sigma fires clickNode
• overlays path edges in highlight color when path prop is set

Production impact

None. Vue's hoisting only breaks ref attachment under @vue/test-utils' mounting strategy. Real page loads work.

Suggested fix

Migrate container from string ref to callback ref (:ref="setContainer"), OR use useTemplateRef() (Vue 3.5+), OR wait for @vue/test-utils 2.5+.

Refs PR #687