Prefer exceptions over silent failures

Raise exceptions instead of returning None, logging warnings, or silently modifying values when encountering error conditions. This makes failures explicit and forces callers to handle error cases properly, improving code reliability and debugging experience.

Why this matters:

• Returning None forces every caller to check for null values, similar to error handling in Go
• Silent failures or logging-only approaches hide problems until they cause issues downstream
• Exceptions provide clear stack traces and force explicit error handling

Apply this by:

• Replace return None for missing resources with specific exceptions
• Use exceptions instead of logging warnings for validation failures
• Avoid silently modifying invalid input values in validators

Example:

# ❌ Avoid - silent failure
def update_schedule(session: Session, schedule_id: str, updates: dict) -> Optional[WorkflowSchedulePlan]:
    schedule = session.get(WorkflowSchedulePlan, schedule_id)
    if not schedule:
        return None  # Forces caller to check for None

# ✅ Prefer - explicit exception
def update_schedule(session: Session, schedule_id: str, updates: dict) -> WorkflowSchedulePlan:
    schedule = session.get(WorkflowSchedulePlan, schedule_id)
    if not schedule:
        raise ValueError(f"Schedule not found: {schedule_id}")
    # ... rest of implementation

Exception: Use None returns only when the absence of a value is a valid business case, not an error condition.