Build UK Microplex replacement dashboard gates

[MaxGhenis]

Umbrella: #2

Create the UK equivalent of the Microplex run board so we can repeatedly compare mp-30k-uk and later mp-300k-uk to eFRS.

Scope:

• Surface pinned eFRS baseline metadata.
• Surface target-loss summaries, target deltas, protected-family deltas, H5 compatibility, record counts, nonzero weights, ESS, H5 size, and benchmark outputs.
• Keep incomplete cells explicit rather than inferring wins from partial artifacts.

Acceptance:

• The dashboard is the source of truth for whether a UK candidate is experimental, beta, or release-track.