Code style rule (always loaded)

Formatter & linter: ruff is the single tool (replaces black / isort / flake8). Line length 88, target py312. Run make format to auto-fix; make lint checks.
Active ruff rule sets: E F I N UP B SIM ASYNC. Don't disable a rule inline unless there's a genuine reason — prefer fixing the code.
Type hints: annotate every public function signature (params + return). The codebase is ~100% typed; keep it that way.
from __future__ import annotations at the top of every module — annotations are strings, so forward refs and X | None unions are free.
Prefer collections.abc (Sequence, Mapping) over concrete list/dict in signatures; use Protocol for structural interfaces.
No dead code: no commented-out blocks, no unused imports, no speculative abstractions. Delete rather than comment out.
Naming: *Manager (orchestrators), *Provider (injectable services), *Reader/*Writer (persistence), *Recaller (search routes). Follow the established suffix when adding a sibling.