- Remove '|| true' from CI type-check job to enforce strict checking
- Begin type narrowing pattern in units.py with _typed property accessors
- Document all 42 type errors across 15 files in roadmap backlog
- Priority: medium, estimated 4-6 hours to complete
Type errors fall into categories:
- Union types not narrowed after __post_init__ coercion
- float() on object types
- Duplicate method definitions
- Provider interface type mismatches
