Add ProofLine criteria documentation and Strategy Catalog v1 implementation

- Add acceptance criteria documentation (AC-0013 through AC-0023)
- Add Line-0003 discovery documentation
- Implement Strategy Catalog v1 with new database migration
- Update portfolio API endpoints and schemas
- Refactor strategy and portfolio services
- Add strategy management CLI commands
- Update domain models with strategy catalog support
- Add comprehensive tests for v1 strategies
- Update design documentation (data model, interfaces, runtime flows)

app/domain/errors.py

@@ -0,0 +1,9 @@
+"""Shared strategy-catalog domain errors used across API, service, and persistence layers."""
+
+
+class StrategyNotFoundError(ValueError):
+    """Raised when a referenced strategy ID does not exist."""
+
+
+class StrategyInactiveError(ValueError):
+    """Raised when a new portfolio selection targets an inactive strategy."""