refactor: migrate templates and static files to self-contained modules

Templates Migration:
- Migrate admin templates to modules (tenancy, billing, monitoring, marketplace, etc.)
- Migrate vendor templates to modules (tenancy, billing, orders, messaging, etc.)
- Migrate storefront templates to modules (catalog, customers, orders, cart, checkout, cms)
- Migrate public templates to modules (billing, marketplace, cms)
- Keep shared templates in app/templates/ (base.html, errors/, partials/, macros/)
- Migrate letzshop partials to marketplace module

Static Files Migration:
- Migrate admin JS to modules: tenancy (23 files), core (5 files), monitoring (1 file)
- Migrate vendor JS to modules: tenancy (4 files), core (2 files)
- Migrate shared JS: vendor-selector.js to core, media-picker.js to cms
- Migrate storefront JS: storefront-layout.js to core
- Keep framework JS in static/ (api-client, utils, money, icons, log-config, lib/)
- Update all template references to use module_static paths

Naming Consistency:
- Rename static/platform/ to static/public/
- Rename app/templates/platform/ to app/templates/public/
- Update all extends and static references

Documentation:
- Update module-system.md with shared templates documentation
- Update frontend-structure.md with new module JS organization

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

tests/unit/services/test_email_service.py

@@ -6,7 +6,7 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 
-from app.services.email_service import (
+from app.modules.messaging.services.email_service import (
     DebugProvider,
     EmailProvider,
     EmailService,
@@ -56,7 +56,7 @@ class TestEmailProviders:
 
         assert success is True
 
-    @patch("app.services.email_service.settings")
+    @patch("app.modules.messaging.services.email_service.settings")
     def test_get_provider_debug_mode(self, mock_settings):
         """Test get_provider returns DebugProvider in debug mode."""
         mock_settings.email_debug = True
@@ -65,7 +65,7 @@ class TestEmailProviders:
 
         assert isinstance(provider, DebugProvider)
 
-    @patch("app.services.email_service.settings")
+    @patch("app.modules.messaging.services.email_service.settings")
     def test_get_provider_smtp(self, mock_settings):
         """Test get_provider returns SMTPProvider for smtp config."""
         mock_settings.email_debug = False
@@ -75,7 +75,7 @@ class TestEmailProviders:
 
         assert isinstance(provider, SMTPProvider)
 
-    @patch("app.services.email_service.settings")
+    @patch("app.modules.messaging.services.email_service.settings")
     def test_get_provider_unknown_defaults_to_smtp(self, mock_settings):
         """Test get_provider defaults to SMTP for unknown providers."""
         mock_settings.email_debug = False
@@ -211,8 +211,8 @@ class TestEmailService:
 class TestEmailSending:
     """Test suite for email sending functionality."""
 
-    @patch("app.services.email_service.get_platform_provider")
-    @patch("app.services.email_service.get_platform_email_config")
+    @patch("app.modules.messaging.services.email_service.get_platform_provider")
+    @patch("app.modules.messaging.services.email_service.get_platform_email_config")
     def test_send_raw_success(self, mock_get_config, mock_get_platform_provider, db):
         """Test successful raw email sending."""
         # Setup mocks
@@ -243,8 +243,8 @@ class TestEmailSending:
         assert log.subject == "Test Subject"
         assert log.provider_message_id == "msg-123"
 
-    @patch("app.services.email_service.get_platform_provider")
-    @patch("app.services.email_service.get_platform_email_config")
+    @patch("app.modules.messaging.services.email_service.get_platform_provider")
+    @patch("app.modules.messaging.services.email_service.get_platform_email_config")
     def test_send_raw_failure(self, mock_get_config, mock_get_platform_provider, db):
         """Test failed raw email sending."""
         # Setup mocks
@@ -272,7 +272,7 @@ class TestEmailSending:
         assert log.status == EmailStatus.FAILED.value
         assert log.error_message == "Connection refused"
 
-    @patch("app.services.email_service.settings")
+    @patch("app.modules.messaging.services.email_service.settings")
     def test_send_raw_email_disabled(self, mock_settings, db):
         """Test email sending when disabled."""
         mock_settings.email_enabled = False
@@ -293,8 +293,8 @@ class TestEmailSending:
         assert log.status == EmailStatus.FAILED.value
         assert "disabled" in log.error_message.lower()
 
-    @patch("app.services.email_service.get_platform_provider")
-    @patch("app.services.email_service.get_platform_email_config")
+    @patch("app.modules.messaging.services.email_service.get_platform_provider")
+    @patch("app.modules.messaging.services.email_service.get_platform_email_config")
     def test_send_template_success(self, mock_get_config, mock_get_platform_provider, db):
         """Test successful template email sending."""
         # Create test template
@@ -586,8 +586,8 @@ class TestSignupWelcomeEmail:
         for var in required_vars:
             assert var in template.variables_list, f"Missing variable: {var}"
 
-    @patch("app.services.email_service.get_platform_provider")
-    @patch("app.services.email_service.get_platform_email_config")
+    @patch("app.modules.messaging.services.email_service.get_platform_provider")
+    @patch("app.modules.messaging.services.email_service.get_platform_email_config")
     def test_welcome_email_send(self, mock_get_config, mock_get_platform_provider, db, welcome_template, test_vendor, test_user):
         """Test sending welcome email."""
         # Setup mocks