feat: add shared task assignments and quick win sorting

app/services/badges.py

@@ -4,7 +4,7 @@ import json
 from collections import defaultdict
 from datetime import date, datetime, time, timedelta
 
-from sqlalchemy import and_
+from sqlalchemy import and_, or_
 
 from ..extensions import db
 from ..models import BadgeDefinition, MonthlyScoreSnapshot, TaskInstance, User, UserBadge
@@ -92,7 +92,7 @@ def _completion_metrics(user: User) -> dict[str, int]:
             metrics["on_time_tasks_completed"] += 1
         if completion_day <= task.due_date - timedelta(days=1):
             metrics["early_tasks_completed"] += 1
-        if task.assigned_user_id and task.assigned_user_id != user.id:
+        if task.assigned_user_ids and user.id not in task.assigned_user_ids:
             metrics["foreign_tasks_completed"] += 1
         max_points = max(max_points, task.points_awarded)
 
@@ -127,7 +127,10 @@ def _user_had_clean_month(user_id: int, year: int, month: int) -> bool:
     start_date = date(year, month, 1)
     end_date = (month_bounds(year, month)[1] - timedelta(days=1)).date()
     tasks = TaskInstance.query.filter(
-        TaskInstance.assigned_user_id == user_id,
+        or_(
+            TaskInstance.assigned_user_id == user_id,
+            TaskInstance.assigned_user_secondary_id == user_id,
+        ),
         TaskInstance.due_date >= start_date,
         TaskInstance.due_date <= end_date,
     ).all()