refactor: migrate vendor auth, profile, team, dashboard, settings to modules

Tenancy module (identity & organizational hierarchy):
- vendor_auth.py: login, logout, /me endpoints
- vendor_profile.py: vendor profile get/update
- vendor_team.py: team management, roles, permissions, invitations

Core module (foundational non-domain features):
- vendor_dashboard.py: dashboard statistics
- vendor_settings.py: localization, business info, letzshop settings

All routes auto-discovered via is_self_contained=True.
Deleted 5 legacy files from app/api/v1/vendor/.

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

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

@@ -2,12 +2,13 @@
 """
 Tenancy module vendor API routes.
 
-Provides public vendor information lookup for:
-- Vendor login pages to display branding
-- Public vendor profile lookup
+Aggregates all vendor tenancy routes:
+- /info/{vendor_code} - Public vendor info lookup
+- /auth/* - Vendor authentication (login, logout, /me)
+- /profile/* - Vendor profile management
+- /team/* - Team member management, roles, permissions
 
-These endpoints do NOT require authentication - they provide
-public information about vendors.
+The tenancy module owns identity and organizational hierarchy.
 """
 
 import logging
@@ -80,3 +81,17 @@ def get_vendor_info(
         owner_email=vendor.company.owner.email,
         owner_username=vendor.company.owner.username,
     )
+
+
+# ============================================================================
+# Aggregate Sub-Routers
+# ============================================================================
+# Include all tenancy vendor routes (auth, profile, team)
+
+from .vendor_auth import vendor_auth_router
+from .vendor_profile import vendor_profile_router
+from .vendor_team import vendor_team_router
+
+vendor_router.include_router(vendor_auth_router, tags=["vendor-auth"])
+vendor_router.include_router(vendor_profile_router, tags=["vendor-profile"])
+vendor_router.include_router(vendor_team_router, tags=["vendor-team"])