Site Health: improve look and consistency of all tests

> The second test here feels much stronger. We provide context to the test and indicate it has passed with a ✅ . I also noted we have inconsistent use of title case and sentence case in the test headings.


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Reported here:
p8oabR-y3-p2#comment-4621

Start with the test interface shown in the attached screenshot and review the referenced report for context. Identify where the test headings and result presentation are defined, then compare all tests for consistent title casing, contextual descriptions, and clear passed indicators. Done means the test views consistently communicate context and status.

Written by the indexing model from the issue text.