TDD expected-fail tests proving bug #821 exists: ContextTierService
has data models for hot/warm/cold tiers but no runtime logic for
promotion (cold→warm→hot on access), demotion (hot→warm→cold on
staleness), or eviction (budget overflow). The service methods either
do not exist or are no-ops.
Three Behave scenarios tagged @tdd_expected_fail @tdd_bug @tdd_bug_821:
1. Promotion on repeated access
2. Demotion on staleness
3. Eviction on hot tier budget overflow
One Robot Framework integration test with 3 subcommands.
ISSUES CLOSED: #840
brent.edwards