PR #919 squash-merged before the test-fix push landed, so main carries the
broken pre-existing tests against the new build_sber_route/SberDashboard API.
Brings the test files to the intended post-#794 state:
- update tests/test_sber_index.py to 3-arg build_sber_route + SberDashboard list
- patch tests/test_estimator_imv_blend.py dkp tests (patch _load_sber_index_series)
- move test_estimator_sber_time_adjust.py to tests/ root, drop dup tests/services/ copies
