refactor: complete module-driven architecture migration

This commit completes the migration to a fully module-driven architecture:

## Models Migration
- Moved all domain models from models/database/ to their respective modules:
  - tenancy: User, Admin, Vendor, Company, Platform, VendorDomain, etc.
  - cms: MediaFile, VendorTheme
  - messaging: Email, VendorEmailSettings, VendorEmailTemplate
  - core: AdminMenuConfig
- models/database/ now only contains Base and TimestampMixin (infrastructure)

## Schemas Migration
- Moved all domain schemas from models/schema/ to their respective modules:
  - tenancy: company, vendor, admin, team, vendor_domain
  - cms: media, image, vendor_theme
  - messaging: email
- models/schema/ now only contains base.py and auth.py (infrastructure)

## Routes Migration
- Moved admin routes from app/api/v1/admin/ to modules:
  - menu_config.py -> core module
  - modules.py -> tenancy module
  - module_config.py -> tenancy module
- app/api/v1/admin/ now only aggregates auto-discovered module routes

## Menu System
- Implemented module-driven menu system with MenuDiscoveryService
- Extended FrontendType enum: PLATFORM, ADMIN, VENDOR, STOREFRONT
- Added MenuItemDefinition and MenuSectionDefinition dataclasses
- Each module now defines its own menu items in definition.py
- MenuService integrates with MenuDiscoveryService for template rendering

## Documentation
- Updated docs/architecture/models-structure.md
- Updated docs/architecture/menu-management.md
- Updated architecture validation rules for new exceptions

## Architecture Validation
- Updated MOD-019 rule to allow base.py in models/schema/
- Created core module exceptions.py and schemas/ directory
- All validation errors resolved (only warnings remain)

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

app/modules/cms/schemas/media.py

@@ -0,0 +1,198 @@
+# app/modules/cms/schemas/media.py
+"""
+Media/file management Pydantic schemas for API validation and responses.
+
+This module provides schemas for:
+- Media library listing
+- File upload responses
+- Media metadata operations
+- Media usage tracking
+"""
+
+from datetime import datetime
+from typing import Any
+
+from pydantic import BaseModel, Field
+
+# ============================================================================
+# SHARED RESPONSE SCHEMAS
+# ============================================================================
+
+
+class MessageResponse(BaseModel):
+    """Generic message response for simple operations."""
+
+    message: str
+
+
+# ============================================================================
+# MEDIA ITEM SCHEMAS
+# ============================================================================
+
+
+class MediaItemResponse(BaseModel):
+    """Single media item response."""
+
+    id: int
+    filename: str
+    original_filename: str | None = None
+    file_url: str
+    url: str | None = None  # Alias for file_url for JS compatibility
+    thumbnail_url: str | None = None
+    media_type: str  # image, video, document
+    mime_type: str | None = None
+    file_size: int | None = None  # bytes
+    width: int | None = None  # for images/videos
+    height: int | None = None  # for images/videos
+    alt_text: str | None = None
+    description: str | None = None
+    folder: str | None = None
+    extra_metadata: dict[str, Any] | None = None
+    created_at: datetime
+    updated_at: datetime | None = None
+
+    model_config = {"from_attributes": True}
+
+    def model_post_init(self, __context: Any) -> None:
+        """Set url from file_url if not provided."""
+        if self.url is None:
+            object.__setattr__(self, "url", self.file_url)
+
+
+class MediaListResponse(BaseModel):
+    """Paginated list of media items."""
+
+    media: list[MediaItemResponse] = []
+    total: int = 0
+    skip: int = 0
+    limit: int = 100
+    message: str | None = None
+
+
+# ============================================================================
+# UPLOAD RESPONSE SCHEMAS
+# ============================================================================
+
+
+class MediaUploadResponse(BaseModel):
+    """Response for single file upload."""
+
+    success: bool = True
+    message: str | None = None
+    media: MediaItemResponse | None = None
+    # Legacy fields for backwards compatibility
+    id: int | None = None
+    file_url: str | None = None
+    thumbnail_url: str | None = None
+    filename: str | None = None
+    file_size: int | None = None
+    media_type: str | None = None
+
+
+class UploadedFileInfo(BaseModel):
+    """Information about a successfully uploaded file."""
+
+    id: int
+    filename: str
+    file_url: str
+    thumbnail_url: str | None = None
+
+
+class FailedFileInfo(BaseModel):
+    """Information about a failed file upload."""
+
+    filename: str
+    error: str
+
+
+class MultipleUploadResponse(BaseModel):
+    """Response for multiple file upload."""
+
+    uploaded_files: list[UploadedFileInfo] = []
+    failed_files: list[FailedFileInfo] = []
+    total_uploaded: int = 0
+    total_failed: int = 0
+    message: str | None = None
+
+
+# ============================================================================
+# MEDIA DETAIL SCHEMAS
+# ============================================================================
+
+
+class MediaDetailResponse(BaseModel):
+    """Detailed media item response with usage info."""
+
+    id: int | None = None
+    filename: str | None = None
+    original_filename: str | None = None
+    file_url: str | None = None
+    thumbnail_url: str | None = None
+    media_type: str | None = None
+    mime_type: str | None = None
+    file_size: int | None = None
+    width: int | None = None
+    height: int | None = None
+    alt_text: str | None = None
+    description: str | None = None
+    folder: str | None = None
+    extra_metadata: dict[str, Any] | None = None
+    created_at: datetime | None = None
+    updated_at: datetime | None = None
+    message: str | None = None
+
+    model_config = {"from_attributes": True}
+
+
+# ============================================================================
+# MEDIA UPDATE SCHEMAS
+# ============================================================================
+
+
+class MediaMetadataUpdate(BaseModel):
+    """Request model for updating media metadata."""
+
+    filename: str | None = Field(None, max_length=255)
+    alt_text: str | None = Field(None, max_length=500)
+    description: str | None = None
+    folder: str | None = Field(None, max_length=100)
+    metadata: dict[str, Any] | None = None  # Named 'metadata' in API, stored as 'extra_metadata'
+
+
+# ============================================================================
+# MEDIA USAGE SCHEMAS
+# ============================================================================
+
+
+class ProductUsageInfo(BaseModel):
+    """Information about product using this media."""
+
+    product_id: int
+    product_name: str
+    usage_type: str  # main_image, gallery, variant, etc.
+
+
+class MediaUsageResponse(BaseModel):
+    """Response showing where media is being used."""
+
+    media_id: int | None = None
+    products: list[ProductUsageInfo] = []
+    other_usage: list[dict[str, Any]] = []
+    total_usage_count: int = 0
+    message: str | None = None
+
+
+# ============================================================================
+# MEDIA OPTIMIZATION SCHEMAS
+# ============================================================================
+
+
+class OptimizationResultResponse(BaseModel):
+    """Response for media optimization operation."""
+
+    media_id: int | None = None
+    original_size: int | None = None
+    optimized_size: int | None = None
+    savings_percent: float | None = None
+    optimized_url: str | None = None
+    message: str | None = None