feat(config): add APP_BASE_URL setting for outbound link construction

Adds app_base_url config (default http://localhost:8000) used for all
outbound URLs: invitation emails, billing checkout redirects, signup
login links, portal return URLs.

Replaces hardcoded https://{main_domain} and localhost:8000 patterns.
Configurable per environment via APP_BASE_URL env var:
- Dev: http://localhost:8000 (or http://acme.localhost:9999)
- Prod: https://wizard.lu

main_domain is preserved for subdomain resolution and cookie config.

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

.env.example

@@ -72,6 +72,11 @@ LOG_FILE=logs/app.log
 # Your main platform domain
 MAIN_DOMAIN=wizard.lu
 
+# Full base URL for outbound links (emails, billing redirects, etc.)
+# Must include protocol and port if non-standard
+# Examples: http://localhost:8000, http://acme.localhost:9999, https://wizard.lu
+APP_BASE_URL=http://localhost:8000
+
 # Custom domain features
 # Enable/disable custom domains
 ALLOW_CUSTOM_DOMAINS=True

app/core/config.py

@@ -98,6 +98,11 @@ class Settings(BaseSettings):
     # =============================================================================
     main_domain: str = "wizard.lu"
 
+    # Full base URL for outbound links (emails, redirects, etc.)
+    # Must include protocol and port if non-standard.
+    # Examples: http://localhost:8000, http://acme.localhost:9999, https://wizard.lu
+    app_base_url: str = "http://localhost:8000"
+
     # Custom domain features
     allow_custom_domains: bool = True
     require_domain_verification: bool = True

app/modules/billing/routes/api/store_addons.py

@@ -144,7 +144,7 @@ def purchase_addon(
     store = billing_service.get_store(db, store_id)
 
     # Build URLs
-    base_url = f"https://{settings.main_domain}"
+    base_url = settings.app_base_url.rstrip("/")
     success_url = f"{base_url}/store/{store.store_code}/billing?addon_success=true"
     cancel_url = f"{base_url}/store/{store.store_code}/billing?addon_cancelled=true"
 

app/modules/billing/routes/api/store_checkout.py

@@ -59,7 +59,7 @@ def create_checkout_session(
 
     store_code = subscription_service.get_store_code(db, store_id)
 
-    base_url = f"https://{settings.main_domain}"
+    base_url = settings.app_base_url.rstrip("/")
     success_url = f"{base_url}/store/{store_code}/billing?success=true"
     cancel_url = f"{base_url}/store/{store_code}/billing?cancelled=true"
 
@@ -87,7 +87,7 @@ def create_portal_session(
     merchant_id, platform_id = subscription_service.resolve_store_to_merchant(db, store_id, current_user.token_platform_id)
 
     store_code = subscription_service.get_store_code(db, store_id)
-    return_url = f"https://{settings.main_domain}/store/{store_code}/billing"
+    return_url = f"{settings.app_base_url.rstrip('/')}/store/{store_code}/billing"
 
     result = billing_service.create_portal_session(db, merchant_id, platform_id, return_url)
 

app/modules/billing/services/signup_service.py

@@ -617,7 +617,7 @@ class SignupService:
 
             # Build login URL
             login_url = (
-                f"https://{settings.main_domain}"
+                f"{settings.app_base_url.rstrip('/')}"
                 f"/store/{store.store_code}/dashboard"
             )
 

app/modules/tenancy/services/store_team_service.py

@@ -981,19 +981,10 @@ class StoreTeamService:
     ):
         """Send team invitation email."""
         from app.core.config import settings as app_settings
-        from app.core.environment import is_production
         from app.modules.messaging.services.email_service import EmailService
 
-        # Build acceptance URL
-        # Prod: https://{subdomain}.{main_domain}/invitation/accept?token=...
-        # Dev:  http://localhost:8000/store/{store_code}/invitation/accept?token=...
-        main_domain = app_settings.main_domain.rstrip("/")
-        if is_production():
-            base_url = f"https://{store.subdomain}.{main_domain}"
-        else:
-            base_url = f"http://localhost:8000/store/{store.store_code}"
-
-        acceptance_link = f"{base_url}/invitation/accept?token={token}"
+        base_url = app_settings.app_base_url.rstrip("/")
+        acceptance_link = f"{base_url}/store/{store.store_code}/invitation/accept?token={token}"
 
         email_service = EmailService(db)
         email_service.send_template(