feat(loyalty): refactor analytics into shared template and add merchant stats API

Extract analytics stat cards, points activity, and location breakdown
into a shared partial used by admin, merchant, and store dashboards.
Add merchant stats API endpoint and client-side merchant filter on admin
analytics page. Extend stats schema with new_this_month and
estimated_liability_cents fields.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/loyalty/services/program_service.py

@@ -322,6 +322,52 @@ class ProgramService:
             db.query(func.count(func.distinct(LoyaltyProgram.merchant_id))).scalar() or 0
         )
 
+        # All-time points
+        total_points_issued = (
+            db.query(func.sum(LoyaltyTransaction.points_delta))
+            .filter(LoyaltyTransaction.points_delta > 0)
+            .scalar()
+            or 0
+        )
+        total_points_redeemed = (
+            db.query(func.sum(func.abs(LoyaltyTransaction.points_delta)))
+            .filter(LoyaltyTransaction.points_delta < 0)
+            .scalar()
+            or 0
+        )
+
+        # Outstanding points balance
+        total_points_balance = (
+            db.query(func.sum(LoyaltyCard.points_balance)).scalar() or 0
+        )
+
+        # New members this month
+        month_start = datetime.now(UTC).replace(day=1, hour=0, minute=0, second=0, microsecond=0)
+        new_this_month = (
+            db.query(func.count(LoyaltyCard.id))
+            .filter(LoyaltyCard.created_at >= month_start)
+            .scalar()
+            or 0
+        )
+
+        # Estimated liability (rough estimate: points / 100 as euros)
+        points_value_cents = total_points_balance // 100 * 100
+        # Stamp liability across all programs
+        stamp_liability = 0
+        programs = db.query(LoyaltyProgram).all()
+        for prog in programs:
+            stamp_value = prog.stamps_reward_value_cents or 0
+            stamps_target = prog.stamps_target or 1
+            current_stamps = (
+                db.query(func.sum(LoyaltyCard.stamp_count))
+                .filter(LoyaltyCard.program_id == prog.id)
+                .scalar()
+                or 0
+            )
+            stamp_liability += current_stamps * stamp_value // stamps_target
+
+        estimated_liability_cents = stamp_liability + points_value_cents
+
         return {
             "total_programs": total_programs,
             "active_programs": active_programs,
@@ -331,6 +377,11 @@ class ProgramService:
             "transactions_30d": transactions_30d,
             "points_issued_30d": points_issued_30d,
             "points_redeemed_30d": points_redeemed_30d,
+            "total_points_issued": total_points_issued,
+            "total_points_redeemed": total_points_redeemed,
+            "total_points_balance": total_points_balance,
+            "new_this_month": new_this_month,
+            "estimated_liability_cents": estimated_liability_cents,
         }
 
     def check_self_enrollment_allowed(self, db: Session, merchant_id: int) -> None:
@@ -843,6 +894,7 @@ class ProgramService:
         }
 
         thirty_days_ago = datetime.now(UTC) - timedelta(days=30)
+        month_start = datetime.now(UTC).replace(day=1, hour=0, minute=0, second=0, microsecond=0)
 
         # Total cards
         stats["total_cards"] = (
@@ -920,6 +972,37 @@ class ProgramService:
             or 0
         )
 
+        # New members this month
+        stats["new_this_month"] = (
+            db.query(func.count(LoyaltyCard.id))
+            .filter(
+                LoyaltyCard.merchant_id == merchant_id,
+                LoyaltyCard.created_at >= month_start,
+            )
+            .scalar()
+            or 0
+        )
+
+        # Estimated liability (unredeemed value)
+        current_stamps = (
+            db.query(func.sum(LoyaltyCard.stamp_count))
+            .filter(LoyaltyCard.merchant_id == merchant_id)
+            .scalar()
+            or 0
+        )
+        stamp_value = program.stamps_reward_value_cents or 0
+        stamps_target = program.stamps_target or 1
+        current_points = (
+            db.query(func.sum(LoyaltyCard.points_balance))
+            .filter(LoyaltyCard.merchant_id == merchant_id)
+            .scalar()
+            or 0
+        )
+        points_value_cents = current_points // 100 * 100
+        stats["estimated_liability_cents"] = (
+            (current_stamps * stamp_value // stamps_target) + points_value_cents
+        )
+
         # Get all stores for this merchant for location breakdown
         stores = store_service.get_stores_by_merchant_id(db, merchant_id)