refactor: migrate modules from re-exports to canonical implementations

Move actual code implementations into module directories:
- orders: 5 services, 4 models, order/invoice schemas
- inventory: 3 services, 2 models, 30+ schemas
- customers: 3 services, 2 models, customer schemas
- messaging: 3 services, 2 models, message/notification schemas
- monitoring: background_tasks_service
- marketplace: 5+ services including letzshop submodule
- dev_tools: code_quality_service, test_runner_service
- billing: billing_service
- contracts: definition.py

Legacy files in app/services/, models/database/, models/schema/
now re-export from canonical module locations for backwards
compatibility. Architecture validator passes with 0 errors.

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

app/modules/messaging/schemas/__init__.py

@@ -2,27 +2,106 @@
 """
 Messaging module Pydantic schemas.
 
-Re-exports messaging-related schemas from their source locations.
+This module contains the canonical implementations of messaging-related schemas.
 """
 
-from models.schema.message import (
-    ConversationResponse,
-    ConversationListResponse,
-    MessageResponse,
-    MessageCreate,
+from app.modules.messaging.schemas.message import (
+    # Attachment schemas
     AttachmentResponse,
+    # Message schemas
+    MessageCreate,
+    MessageResponse,
+    # Participant schemas
+    ParticipantInfo,
+    ParticipantResponse,
+    # Conversation schemas
+    ConversationCreate,
+    ConversationSummary,
+    ConversationDetailResponse,
+    ConversationListResponse,
+    ConversationResponse,
+    # Unread count
+    UnreadCountResponse,
+    # Notification preferences
+    NotificationPreferencesUpdate,
+    # Conversation actions
+    CloseConversationResponse,
+    ReopenConversationResponse,
+    MarkReadResponse,
+    # Recipient selection
+    RecipientOption,
+    RecipientListResponse,
+    # Admin schemas
+    AdminConversationSummary,
+    AdminConversationListResponse,
+    AdminMessageStats,
 )
-from models.schema.notification import (
+
+from app.modules.messaging.schemas.notification import (
+    # Response schemas
+    MessageResponse as NotificationMessageResponse,
+    UnreadCountResponse as NotificationUnreadCountResponse,
+    # Notification schemas
     NotificationResponse,
     NotificationListResponse,
+    # Settings schemas
+    NotificationSettingsResponse,
+    NotificationSettingsUpdate,
+    # Template schemas
+    NotificationTemplateResponse,
+    NotificationTemplateListResponse,
+    NotificationTemplateUpdate,
+    # Test notification
+    TestNotificationRequest,
+    # Alert statistics
+    AlertStatisticsResponse,
 )
 
 __all__ = [
-    "ConversationResponse",
-    "ConversationListResponse",
-    "MessageResponse",
-    "MessageCreate",
+    # Attachment schemas
     "AttachmentResponse",
+    # Message schemas
+    "MessageCreate",
+    "MessageResponse",
+    # Participant schemas
+    "ParticipantInfo",
+    "ParticipantResponse",
+    # Conversation schemas
+    "ConversationCreate",
+    "ConversationSummary",
+    "ConversationDetailResponse",
+    "ConversationListResponse",
+    "ConversationResponse",
+    # Unread count
+    "UnreadCountResponse",
+    # Notification preferences
+    "NotificationPreferencesUpdate",
+    # Conversation actions
+    "CloseConversationResponse",
+    "ReopenConversationResponse",
+    "MarkReadResponse",
+    # Recipient selection
+    "RecipientOption",
+    "RecipientListResponse",
+    # Admin schemas
+    "AdminConversationSummary",
+    "AdminConversationListResponse",
+    "AdminMessageStats",
+    # Notification response schemas
+    "NotificationMessageResponse",
+    "NotificationUnreadCountResponse",
+    # Notification schemas
     "NotificationResponse",
     "NotificationListResponse",
+    # Settings schemas
+    "NotificationSettingsResponse",
+    "NotificationSettingsUpdate",
+    # Template schemas
+    "NotificationTemplateResponse",
+    "NotificationTemplateListResponse",
+    "NotificationTemplateUpdate",
+    # Test notification
+    "TestNotificationRequest",
+    # Alert statistics
+    "AlertStatisticsResponse",
 ]