fix(ui): inject window.FRONTEND_TYPE from server + rename SHOP→STOREFRONT

Server now injects window.FRONTEND_TYPE in all base templates via
get_context_for_frontend(). Both log-config.js and dev-toolbar.js read
this instead of guessing from URL paths, fixing:
- UNKNOWN prefix on merchant pages
- Incorrect detection on custom domains/subdomains in prod

Also adds frontend_type to login page contexts (admin, merchant, store).

Renames all [SHOP] logger prefixes to [STOREFRONT] across 7 files
(storefront-layout.js + 6 storefront templates).

Adds 'merchant' and 'storefront' to log-config.js frontend detection,
log levels, and logger selection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -62,6 +62,7 @@ async def admin_login_page(
     context = {
         "request": request,
         "current_language": language,
+        "frontend_type": "admin",
         **get_jinja2_globals(language),
     }
     return templates.TemplateResponse("tenancy/admin/login.html", context)

app/modules/core/routes/pages/merchant.py

@@ -72,6 +72,7 @@ async def merchant_login_page(
     context = {
         "request": request,
         "current_language": language,
+        "frontend_type": "merchant",
         **get_jinja2_globals(language),
     }
     return templates.TemplateResponse("tenancy/merchant/login.html", context)