refactor: remove backward compatibility code for pre-launch baseline

Clean up accumulated backward-compat shims, deprecated wrappers, unused
aliases, and legacy code across the codebase. Since the platform is not
live yet, this establishes a clean baseline.

Changes:
- Delete deprecated middleware/context.py (RequestContext, get_request_context)
- Remove unused factory get_store_email_settings_service()
- Remove deprecated pagination_full macro, /admin/platform-homepage route
- Remove ConversationResponse, InvoiceSettings* unprefixed aliases
- Simplify celery_config.py (remove empty LEGACY_TASK_MODULES)
- Standardize billing exceptions: *Error aliases → *Exception names
- Consolidate duplicate TierNotFoundError/FeatureNotFoundError classes
- Remove deprecated is_admin_request() from Store/PlatformContextManager
- Remove is_platform_default field, MediaUploadResponse legacy flat fields
- Remove MediaItemResponse.url alias, update JS to use file_url
- Update all affected tests and documentation

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

app/modules/cms/routes/pages/admin.py

@@ -6,7 +6,7 @@ Admin pages for managing platform and store content pages.
 """
 
 from fastapi import APIRouter, Depends, Path, Request
-from fastapi.responses import HTMLResponse, RedirectResponse
+from fastapi.responses import HTMLResponse
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_db, require_menu_access
@@ -22,22 +22,6 @@ router = APIRouter()
 # ============================================================================
 
 
-@router.get("/platform-homepage", include_in_schema=False)
-async def admin_platform_homepage_manager(
-    request: Request,
-    current_user: User = Depends(require_menu_access("platforms", FrontendType.ADMIN)),
-    db: Session = Depends(get_db),
-):
-    """
-    Deprecated: Redirects to platforms page.
-
-    Platform homepages are now managed via:
-    - /admin/platforms → Select platform → Homepage button
-    - Or directly: /admin/content-pages?platform_code={code}&slug=home
-    """
-    return RedirectResponse(url="/admin/platforms", status_code=302)
-
-
 @router.get("/content-pages", response_class=HTMLResponse, include_in_schema=False)
 async def admin_content_pages_list(
     request: Request,

app/modules/cms/schemas/content_page.py

@@ -90,7 +90,6 @@ class ContentPageResponse(BaseModel):
     show_in_header: bool
     show_in_legal: bool
     is_platform_page: bool = False
-    is_platform_default: bool = False  # Deprecated: use is_platform_page
     is_store_default: bool = False
     is_store_override: bool = False
     page_tier: str | None = None

app/modules/cms/schemas/media.py

@@ -37,7 +37,6 @@ class MediaItemResponse(BaseModel):
     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
@@ -53,11 +52,6 @@ class MediaItemResponse(BaseModel):
 
     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."""
@@ -80,13 +74,6 @@ class MediaUploadResponse(BaseModel):
     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):

app/modules/cms/services/__init__.py

@@ -15,7 +15,6 @@ from app.modules.cms.services.media_service import (
 )
 from app.modules.cms.services.store_email_settings_service import (
     StoreEmailSettingsService,
-    get_store_email_settings_service,  # Deprecated: use store_email_settings_service
     store_email_settings_service,
 )
 from app.modules.cms.services.store_theme_service import (
@@ -32,5 +31,4 @@ __all__ = [
     "store_theme_service",
     "StoreEmailSettingsService",
     "store_email_settings_service",
-    "get_store_email_settings_service",  # Deprecated
 ]

app/modules/cms/services/store_email_settings_service.py

@@ -481,14 +481,3 @@ class StoreEmailSettingsService:
 
 # Module-level service instance (singleton pattern)
 store_email_settings_service = StoreEmailSettingsService()
-
-
-# Deprecated: Factory function for backwards compatibility
-def get_store_email_settings_service(db: Session) -> StoreEmailSettingsService:
-    """
-    Factory function to get a StoreEmailSettingsService instance.
-
-    Deprecated: Use the singleton `store_email_settings_service` instead and pass
-    `db` to individual methods.
-    """
-    return store_email_settings_service

app/modules/cms/static/shared/js/media-picker.js

@@ -262,9 +262,9 @@ function mediaPickerMixin(storeIdGetter, multiSelect = false) {
          */
         setMainImage(media) {
             if (this.form) {
-                this.form.primary_image_url = media.url;
+                this.form.primary_image_url = media.file_url;
             }
-            mediaPickerLog.info('Main image set:', media.url);
+            mediaPickerLog.info('Main image set:', media.file_url);
         },
 
         /**
@@ -272,13 +272,13 @@ function mediaPickerMixin(storeIdGetter, multiSelect = false) {
          */
         addAdditionalImages(mediaList) {
             if (this.form && Array.isArray(this.form.additional_images)) {
-                const newUrls = mediaList.map(m => m.url);
+                const newUrls = mediaList.map(m => m.file_url);
                 this.form.additional_images = [
                     ...this.form.additional_images,
                     ...newUrls
                 ];
             }
-            mediaPickerLog.info('Additional images added:', mediaList.map(m => m.url));
+            mediaPickerLog.info('Additional images added:', mediaList.map(m => m.file_url));
         },
 
         /**

app/modules/cms/static/store/js/content-pages.js

@@ -73,7 +73,7 @@ function storeContentPagesManager() {
 
                 // Platform pages - filter to only show actual platform defaults
                 const allPages = platformResponse.data || platformResponse || [];
-                this.platformPages = allPages.filter(p => p.is_platform_default);
+                this.platformPages = allPages.filter(p => p.is_platform_page);
 
                 // Store's custom pages (includes overrides)
                 this.customPages = storeResponse.data || storeResponse || [];