feat: monthly_stats() — médiane journalière et hebdomadaire

app/business/time_calc.py

@@ -25,6 +25,30 @@ def week_balance_minutes(actual_minutes: int, reference_minutes: int) -> int:
     return actual_minutes - reference_minutes
 
 
+import statistics as _stats
+
+
+def monthly_stats(entries: list) -> dict:
+    """
+    Calcule médiane journalière et médiane hebdomadaire (semaines ISO)
+    pour un groupe d'entrées. Les absences (total_minutes=0) sont incluses.
+    """
+    if not entries:
+        return {"median_daily_min": 0, "median_weekly_min": 0}
+
+    daily = [e.total_minutes() for e in entries]
+    median_daily = int(_stats.median(daily))
+
+    weekly: dict[tuple, int] = {}
+    for e in entries:
+        key = e.date.isocalendar()[:2]  # (year, isoweek)
+        weekly[key] = weekly.get(key, 0) + e.total_minutes()
+
+    median_weekly = int(_stats.median(weekly.values()))
+
+    return {"median_daily_min": median_daily, "median_weekly_min": median_weekly}
+
+
 def count_day_types(entries: list) -> dict[str, int]:
     """Retourne un dict {day_type: count} pour une liste d'entrées, sans les zéros."""
     counts: dict[str, int] = {}