Contributions

class Contribution:
    user                    # Who made the contribution
    contribution_type       # What type of contribution
    category               # Validator, Builder, or Steward
    points                 # Base points awarded (within min/max)
    frozen_global_points   # Base points × multiplier (frozen)
    multiplier_at_creation # Multiplier rate when created
    contribution_date      # When the contribution was made
    notes                  # Additional context
    evidence_items         # Links and descriptions

# Get the active multiplier for the contribution date
multiplier = GlobalLeaderboardMultiplier.get_active_for_type(
    contribution_type=contribution_type,
    at_date=contribution_date
)

# Calculate frozen global points
frozen_global_points = base_points * multiplier

if not user.visible:
    raise ValidationError(
        "Cannot add contributions for invisible users"
    )

if points < contribution_type.min_points or 
   points > contribution_type.max_points:
    raise ValidationError(
        f"Points must be between {min_points} and {max_points}"
    )

multiplier = GlobalLeaderboardMultiplier.get_active_for_type(
    contribution_type,
    at_date=contribution_date
)
if not multiplier:
    raise ValidationError(
        "No active multiplier exists for this date"
    )

class Mission:
    name               # Mission title
    description        # What participants should do
    contribution_type  # Associated contribution type
    start_date        # When it becomes active
    end_date          # When it expires

class ContributionHighlight:
    contribution  # The featured contribution
    title        # Short highlight title
    description  # Why this contribution is noteworthy

# List contributions
GET /api/v1/contributions/

# Get specific contribution
GET /api/v1/contributions/{id}/

# Create submission (requires auth)
POST /api/v1/contributions/

# Update submission (requires auth)
PATCH /api/v1/contributions/{id}/

# Delete submission (requires auth)
DELETE /api/v1/contributions/{id}/