Add release smoke gates to Microplex dashboard

[MaxGhenis]

Summary

• surface colocated runtime/file-size release smoke results in dashboard score rows and the Microplex current-best comparison row
• infer mp record-count tiers from artifact names or measured household counts
• stop ranking stale 0.097-baseline latest-PE artifacts as current latest-us-data results
• keep dashboard run-contract tests independent of the untracked run-contract writer module

Validation

• /Users/maxghenis/.local/bin/uv run --python 3.13 --extra dev ruff check src/microplex_us/pipelines/dashboard.py tests/pipelines/test_dashboard.py
• /Users/maxghenis/.local/bin/uv run --python 3.13 --extra dev ruff format --check src/microplex_us/pipelines/dashboard.py tests/pipelines/test_dashboard.py
• /Users/maxghenis/.local/bin/uv run --python 3.13 --extra dev pytest -q tests/pipelines/test_dashboard.py

Dashboard refresh

• Refreshed /Users/maxghenis/CosilicoAI/microplex-us/artifacts/microplex_dashboard_current.json from real artifacts.
• Current best latest-us-data score is mp-152k, loss 0.0713 vs latest eCPS 0.1698, but it fails release smoke: file-size ratio 2.0002 and runtime ratio 2.256.
• Best release-passing row is mp-120k, loss 0.0936 vs latest eCPS 0.1664, file-size ratio 1.3608 and runtime ratio 1.1928.