Instruments FeatureEvaluationService with System.Diagnostics.Metrics (Counter + IMeterFactory). Accumulates per-feature/day evaluation counts in-process, flushed every 30s to a new FeatureUsageDaily Postgres table via PostgreSQL ON CONFLICT upsert. Caches dashboard query results for 180s in IMemoryCache. New GET /api/v1/environments/{id}/usage endpoint returns top-10 features last day and 14-day per-day breakdown. Admin dashboard shows two ApexCharts bar charts: top features and evaluations by day with per-flag hover tooltip.
Remove duplicate source files from old ApiKeys/, Authentication/, and
Authorization/ folders that were already migrated to Common/Security/.
Update test namespace usings to match. Pin EFC Relational 10.0.5 to
resolve MSB3277 version conflict with Npgsql's transitive dependency.
Add LangVersion and TreatWarningsAsErrors to AppHost and ServiceDefaults.
NUnit integration tests that target a running API by URL and seed/clean
data directly in Postgres. Settings (BaseUrl, DbConnectionString) come
from .runsettings or environment variables so tests can be pointed at
any environment. HTTP requests live in HttpFiles/*.http; assertion
failures include a fresh DB snapshot of the relevant rows. First test
covers the flag-enabled path.
