refactor: fix architecture violations with provider patterns and dependency inversion

Major changes:
- Add AuditProvider protocol for cross-module audit logging
- Move customer order operations to orders module (dependency inversion)
- Add customer order metrics via MetricsProvider pattern
- Fix missing db parameter in get_admin_context() calls
- Move ProductMedia relationship to catalog module (proper ownership)
- Add marketplace breakdown stats to marketplace_widgets

New files:
- contracts/audit.py - AuditProviderProtocol
- core/services/audit_aggregator.py - Aggregates audit providers
- monitoring/services/audit_provider.py - Monitoring audit implementation
- orders/services/customer_order_service.py - Customer order operations
- orders/routes/api/vendor_customer_orders.py - Customer order endpoints
- catalog/services/product_media_service.py - Product media service
- Architecture documentation for patterns

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/tenancy/routes/api/admin_platform_users.py

@@ -9,11 +9,12 @@ by the global exception handler.
 
 import logging
 
-from fastapi import APIRouter, Body, Depends, Path, Query
+from fastapi import APIRouter, Body, Depends, Path, Query, Request
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_admin_api
 from app.core.database import get_db
+from app.modules.core.services.stats_aggregator import stats_aggregator
 from app.modules.tenancy.services.admin_service import admin_service
 from models.schema.auth import UserContext
 from models.schema.auth import (
@@ -104,25 +105,60 @@ def create_user(
     )
 
 
+def _get_platform_id(request: Request, current_admin: UserContext) -> int:
+    """Get platform_id from available sources."""
+    # From JWT token
+    if current_admin.token_platform_id:
+        return current_admin.token_platform_id
+    # From request state
+    platform = getattr(request.state, "platform", None)
+    if platform:
+        return platform.id
+    # First accessible platform
+    if current_admin.accessible_platform_ids:
+        return current_admin.accessible_platform_ids[0]
+    # Fallback
+    return 1
+
+
 @admin_platform_users_router.get("/stats")
 def get_user_statistics(
+    request: Request,
     db: Session = Depends(get_db),
     current_admin: UserContext = Depends(get_current_admin_api),
 ):
-    """Get user statistics for admin dashboard (Admin only)."""
-    try:
-        from app.modules.analytics.services.stats_service import stats_service
+    """Get user statistics for admin dashboard (Admin only).
 
-        return stats_service.get_user_statistics(db)
-    except ImportError:
-        # Analytics module not available - return empty stats
-        logger.warning("Analytics module not available for user statistics")
-        return {
-            "total_users": 0,
-            "active_users": 0,
-            "inactive_users": 0,
-            "admin_users": 0,
-        }
+    Uses the stats_aggregator to get user metrics from the tenancy module's
+    MetricsProvider, ensuring no cross-module import violations.
+    """
+    platform_id = _get_platform_id(request, current_admin)
+
+    # Get metrics from stats_aggregator (tenancy module provides user stats)
+    metrics = stats_aggregator.get_admin_dashboard_stats(db=db, platform_id=platform_id)
+
+    # Extract user stats from tenancy metrics
+    tenancy_metrics = metrics.get("tenancy", [])
+
+    # Build response from metric values
+    stats = {
+        "total_users": 0,
+        "active_users": 0,
+        "inactive_users": 0,
+        "admin_users": 0,
+    }
+
+    for metric in tenancy_metrics:
+        if metric.key == "tenancy.total_users":
+            stats["total_users"] = int(metric.value)
+        elif metric.key == "tenancy.active_users":
+            stats["active_users"] = int(metric.value)
+        elif metric.key == "tenancy.inactive_users":
+            stats["inactive_users"] = int(metric.value)
+        elif metric.key == "tenancy.admin_users":
+            stats["admin_users"] = int(metric.value)
+
+    return stats
 
 
 @admin_platform_users_router.get("/search", response_model=UserSearchResponse)