Moved logging.basicConfig() to app/main.py as the single source of truth.
Removed duplicate (no-op) calls from app/db_engine.py, app/dependencies.py,
and all 30 router files in app/routers_v2/. Removed the now-unused LOG_DATA
dict and date/log_level locals from dependencies.py and db_engine.py.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>