Brownfield dashboard fixture

The baseline (health and projects) is implemented. The new document metadata methods intentionally fail.

node --test --test-concurrency=1 baseline.test.mjs
node --test --test-concurrency=1 feature.test.mjs

Read requirements.md, preserve the baseline, and implement the new methods. The trusted fixture actor is a test seam, not a production identity provider.

Instructor check in the original checkout:

HANDS_ON_REFERENCE=1 node --test --test-concurrency=1 baseline.test.mjs feature.test.mjs