register and sign in pages

backend/core/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class CoreConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "core"

backend/core/exceptions.py

@@ -0,0 +1,32 @@
+"""A single response shape for every error the API returns.
+
+    {"detail": "...", "code": "...", "errors": {"field": ["..."]}}
+
+`errors` is only present for validation failures. The SPA reads `code` to
+branch (e.g. `registration_required`) and `detail` to show a message.
+"""
+
+from rest_framework import exceptions
+from rest_framework.views import exception_handler as drf_exception_handler
+
+
+def exception_handler(exc, context):
+    response = drf_exception_handler(exc, context)
+    if response is None:
+        return None
+
+    code = getattr(exc, "default_code", "error")
+    data = response.data
+
+    if isinstance(exc, exceptions.ValidationError):
+        detail = "The submitted data was invalid."
+        if isinstance(data, dict):
+            non_field = data.get("detail") or data.get("non_field_errors")
+            if non_field:
+                detail = non_field[0] if isinstance(non_field, list) else str(non_field)
+        response.data = {"detail": str(detail), "code": code, "errors": data}
+        return response
+
+    detail = data.get("detail") if isinstance(data, dict) else data
+    response.data = {"detail": str(detail), "code": code}
+    return response

backend/core/pagination.py

@@ -0,0 +1,6 @@
+from rest_framework.pagination import PageNumberPagination
+
+
+class DefaultPagination(PageNumberPagination):
+    page_size_query_param = "page_size"
+    max_page_size = 100

backend/core/urls.py

@@ -0,0 +1,7 @@
+from django.urls import path
+
+from .views import healthcheck
+
+urlpatterns = [
+    path("health/", healthcheck, name="healthcheck"),
+]

backend/core/views.py

@@ -0,0 +1,17 @@
+from django.db import connection
+from rest_framework.decorators import api_view, authentication_classes, permission_classes
+from rest_framework.response import Response
+
+
+@api_view(["GET"])
+@authentication_classes([])
+@permission_classes([])
+def healthcheck(request):
+    """Liveness + database reachability, for compose/nginx health probes."""
+    try:
+        with connection.cursor() as cursor:
+            cursor.execute("SELECT 1")
+        database = "up"
+    except Exception:  # pragma: no cover - reported, not raised
+        database = "down"
+    return Response({"status": "ok", "database": database})