feat(merchant): extract merchant portal as first-class frontend with auth, Tailwind fixes, and Gitea CI

- Extract login/dashboard from billing module into core (matching admin pattern)
- Add merchant auth API with path-isolated cookies (path=/merchants)
- Add merchant base layout with sidebar/header partials and Alpine.js init
- Add frontend detection and login redirect for MERCHANT type
- Wire merchant token in shared api-client.js (get/clear)
- Migrate billing templates to merchant base with dark mode support
- Fix Tailwind: rename shop→storefront in sources and config
- DRY Makefile tailwind targets with TAILWIND_FRONTENDS loop
- Rebuild all Tailwind outputs (production minified)
- Add Gitea Actions CI workflow (ruff, pytest, architecture, docs)
- Add Gitea deployment documentation

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

app/modules/tenancy/routes/api/merchant.py

@@ -2,9 +2,9 @@
 """
 Tenancy module merchant API routes.
 
-Provides merchant-facing API endpoints for the merchant portal:
-- /account/stores - List merchant's stores
-- /account/profile - Get/update merchant profile
+Aggregates all merchant tenancy routes:
+- /auth/* - Merchant authentication (login, logout, /me)
+- /account/* - Merchant account management (stores, profile)
 
 Auto-discovered by the route system (merchant.py in routes/api/).
 """
@@ -21,13 +21,17 @@ from app.core.database import get_db
 from app.modules.tenancy.models import Merchant
 from models.schema.auth import UserContext
 
+from .merchant_auth import merchant_auth_router
+
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
 
-ROUTE_CONFIG = {
-    "prefix": "/account",
-}
+# Include auth routes (/auth/login, /auth/logout, /auth/me)
+router.include_router(merchant_auth_router, tags=["merchant-auth"])
+
+# Account routes are defined below with /account prefix
+_account_router = APIRouter(prefix="/account")
 
 
 # ============================================================================
@@ -81,11 +85,11 @@ def _get_user_merchant(db: Session, user_context: UserContext) -> Merchant:
 
 
 # ============================================================================
-# ENDPOINTS
+# ACCOUNT ENDPOINTS
 # ============================================================================
 
 
-@router.get("/stores")
+@_account_router.get("/stores")
 async def merchant_stores(
     request: Request,
     current_user: UserContext = Depends(get_current_merchant_from_cookie_or_header),
@@ -114,7 +118,7 @@ async def merchant_stores(
     return {"stores": stores}
 
 
-@router.get("/profile")
+@_account_router.get("/profile")
 async def merchant_profile(
     request: Request,
     current_user: UserContext = Depends(get_current_merchant_from_cookie_or_header),
@@ -140,7 +144,7 @@ async def merchant_profile(
     }
 
 
-@router.put("/profile")
+@_account_router.put("/profile")
 async def update_merchant_profile(
     request: Request,
     profile_data: MerchantProfileUpdate,
@@ -177,3 +181,7 @@ async def update_merchant_profile(
         "tax_number": merchant.tax_number,
         "is_verified": merchant.is_verified,
     }
+
+
+# Include account routes in main router
+router.include_router(_account_router, tags=["merchant-account"])