docs(ru): translate requirements-and-sprint-plan.md to Russian (T5.2.2)

docs(ru): translate improvement-plan-2026-q3.md to Russian (T5.2.2)

docs(ru): translate etl-operations.md to Russian (T5.2.2)

docs(ru): translate compliance-requirements.md to Russian (T5.2.2)

docs(ru): translate sprint-plan-2026-s3-updated.md to Russian (T5.2.2)

docs(ru): translate secrets-rotation.md to Russian (T5.2.2)

docs(ru): translate project-checklist.md to Russian (T5.2.2)

fix: zero mypy errors across proxy/app/ (S6.1.3)

fix: mypy type annotations in slm_trainer.py and migrations.py (S6.1.3)

fix: mypy type annotations in chat.py, health.py, graph.py (S6.1.3)

fix: type-ignore on reranker_trainer.py peft fallbacks (S6.1.3)

fix: type-ignore on OTLPSpanExporter=None assignment (S6.1.3)

docs(ru): translate sprint-plan-2026-s3.md to Russian (T5.2.2)

docs(ru): translate sprint-plan-2026-s4.md to Russian (T5.2.2)

docs(ru): translate performance-baselines.md to Russian (T5.2.2)

docs(ru): translate database-migrations.md to Russian (T5.2.2)

docs(ru): translate security-audit-2026-07-16.md to Russian (T5.2.2)

docs(ru): translate architecture-overview.md to Russian (T5.2.2)

docs(ru): translate maturity-report.md to Russian (T5.2.2)

docs(ru): translate observability.md to Russian (T5.2.2)