🌐 i18n(app): relocate locale middleware for improved organization

- move add_locale_to_request middleware above session middleware
- enhance code readability and maintainability by organizing middleware setup

app/main.py

@@ -44,6 +44,15 @@ if not SESSION_SECRET or SESSION_SECRET.startswith("CHANGE_ME"):
 
 SESSION_COOKIE_SECURE = os.getenv("SESSION_COOKIE_SECURE", "1") != "0"
 
+
+@app.middleware("http")
+async def add_locale_to_request(request: Request, call_next):
+    request.state.locale = resolve_locale(request)
+    response = await call_next(request)
+    return response
+
+
+# Session middleware (server-side session based on signed cookie)
 app.add_middleware(
     SessionMiddleware,
     secret_key=SESSION_SECRET,
@@ -54,13 +63,6 @@ app.add_middleware(
 )
 
 
-@app.middleware("http")
-async def add_locale_to_request(request: Request, call_next):
-    request.state.locale = resolve_locale(request)
-    response = await call_next(request)
-    return response
-
-
 @pass_context
 def _t(ctx, key: str, **kwargs) -> str:
     request = ctx.get("request")