unified-list: fix multiple entity rows showing same hover state

[aquaductape]

Multiple entity rows are showing same hover state, showing mark as down checkbox, due to hover condition is compared by entity.id.

Fix is changing hover comparison to entity component id.

[github-actions]

Preview: https://caleb-fix-entity-hover-logic-udic0l.preview.macro.com/app (a29e114)

[claude]

Code review

This PR fixes a bug where multiple entity rows show the same hover state. The implementation correctly addresses the issue by using Symbol() to create unique identifiers for each component instance.

However, there is one compliance issue:

Missing Test for Bug Fix

Issue: The CLAUDE.md testing guidelines require that bug fixes include tests to identify the issue before fixing it:

"Testing - Write tests for your changes. When fixing bugs or regressions, identify the issue with a test before fixing it."

Recommendation: Add tests that verify:

1. Multiple entity rows with the same entity.id maintain independent hover states
2. Hovering over one entity row does not trigger the hover state on other rows with the same entity ID

This will help prevent regression of this bug in the future.

---

Technical review: The code changes themselves are correct - using Symbol() per component instance ensures each rendered entity has a unique identifier, preventing the hover state collision that occurred when using the shared entity.id.