feat: platform-aware storefront routing and billing improvements

Overhaul storefront URL routing to be platform-aware:
- Dev: /platforms/{code}/storefront/{store_code}/
- Prod: subdomain.platform.lu/ (internally rewritten to /storefront/)
- Add subdomain detection in PlatformContextMiddleware
- Add /storefront/ path rewrite for prod mode (subdomain/custom domain)
- Remove all silent platform fallbacks (platform_id=1)
- Add require_platform dependency for clean endpoint validation
- Update route registration, templates, module definitions, base_url calc
- Update StoreContextMiddleware for /storefront/ path detection
- Remove /stores/ from FrontendDetector STOREFRONT_PATH_PREFIXES

Billing service improvements:
- Add store_platform_sync_service to keep store_platforms in sync
- Make tier lookups platform-aware across billing services
- Add tiers for all platforms in seed data
- Add demo subscriptions to seed

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

main.py

@@ -22,7 +22,7 @@ from datetime import UTC, datetime
 from pathlib import Path
 
 import sentry_sdk
-from fastapi import Depends, FastAPI, HTTPException, Request, Response
+from fastapi import Depends, FastAPI, Response
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse, HTMLResponse, RedirectResponse
 from fastapi.staticfiles import StaticFiles
@@ -435,13 +435,13 @@ for route_info in store_page_routes:
 # STOREFRONT PAGES (Customer Shop)
 # =============================================================================
 # Customer shop pages - Register at TWO prefixes:
-# 1. /storefront/* (for subdomain/custom domain modes)
-# 2. /stores/{code}/storefront/* (for path-based development mode)
+# 1. /storefront/* (for prod: subdomain/custom domain, after path rewrite by middleware)
+# 2. /storefront/{store_code}/* (for dev: path-based, after /platforms/{code}/ strip)
 logger.info("Auto-discovering storefront page routes...")
 storefront_page_routes = get_storefront_page_routes()
 logger.info(f"  Found {len(storefront_page_routes)} storefront page route modules")
 
-# Register at /storefront/* (direct access)
+# Register at /storefront/* (prod mode — middleware rewrites /products → /storefront/products)
 logger.info("  Registering storefront routes at /storefront/*")
 for route_info in storefront_page_routes:
     prefix = f"/storefront{route_info.custom_prefix}" if route_info.custom_prefix else "/storefront"
@@ -453,10 +453,10 @@ for route_info in storefront_page_routes:
         include_in_schema=False,
     )
 
-# Register at /stores/{code}/storefront/* (path-based development mode)
-logger.info("  Registering storefront routes at /stores/{code}/storefront/*")
+# Register at /storefront/{store_code}/* (dev mode — /platforms/oms/storefront/WIZATECH/...)
+logger.info("  Registering storefront routes at /storefront/{store_code}/*")
 for route_info in storefront_page_routes:
-    prefix = f"/stores/{{store_code}}/storefront{route_info.custom_prefix}" if route_info.custom_prefix else "/stores/{store_code}/storefront"
+    prefix = f"/storefront/{{store_code}}{route_info.custom_prefix}" if route_info.custom_prefix else "/storefront/{store_code}"
     app.include_router(
         route_info.router,
         prefix=prefix,
@@ -465,49 +465,6 @@ for route_info in storefront_page_routes:
     )
 
 
-# Add handler for /stores/{store_code}/ root path
-@app.get(
-    "/stores/{store_code}/", response_class=HTMLResponse, include_in_schema=False
-)
-async def store_root_path(
-    store_code: str, request: Request, db: Session = Depends(get_db)
-):
-    """Handle store root path (e.g., /stores/orion/)"""
-    # Store should already be in request.state from middleware
-    store = getattr(request.state, "store", None)
-    platform = getattr(request.state, "platform", None)
-
-    if not store:
-        raise HTTPException(status_code=404, detail=f"Store '{store_code}' not found")
-
-    from app.modules.cms.services import content_page_service
-    from app.modules.core.utils.page_context import get_storefront_context
-
-    # Get platform_id (use platform from context or default to 1 for OMS)
-    platform_id = platform.id if platform else 1
-
-    # Try to find landing page (with three-tier resolution)
-    landing_page = content_page_service.get_page_for_store(
-        db, platform_id=platform_id, slug="landing", store_id=store.id, include_unpublished=False
-    )
-
-    if not landing_page:
-        landing_page = content_page_service.get_page_for_store(
-            db, platform_id=platform_id, slug="home", store_id=store.id, include_unpublished=False
-        )
-
-    if landing_page:
-        # Render landing page with selected template
-        template_name = landing_page.template or "default"
-        template_path = f"store/landing-{template_name}.html"
-
-        return templates.TemplateResponse(
-            template_path, get_storefront_context(request, db=db, page=landing_page)
-        )
-    # No landing page - redirect to shop
-    return RedirectResponse(url=f"/stores/{store_code}/storefront/", status_code=302)
-
-
 # ============================================================================
 # PLATFORM ROUTING (via PlatformContextMiddleware)
 #