## Summary
**What is the goal of this PR?**
Small cleanup to make getTheme and getMetrics methods on UITheme const.
They return const refs, so updated call sites to use `const auto&`.
Realistically this won't make much performance difference, but it better
conveys the nature of theme metrics being shared const state.
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### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
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