Implement NetKingdom identity shell for coulomb.social (CSOC-WP-0002)

Django scaffold aligned with the business delivery lane: tenant-keyed
Member model without passwords, identity app as sole OIDC/session
boundary, dev-claims login, authenticated /app/ shell, ADR-0001, and
tests. T01/T02/T05/T06 done; OIDC registration, real user-engine HTTP,
flex-auth, and packaging remain open.

coulomb_social/apps/core/apps.py

@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class CoreConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "coulomb_social.apps.core"
+    label = "core"

coulomb_social/apps/core/context_processors.py

@@ -0,0 +1,9 @@
+from django.conf import settings
+
+
+def site_context(request):
+    return {
+        "site_name": "coulomb.social",
+        "default_tenant_id": settings.DEFAULT_TENANT_ID,
+        "oidc_enabled": settings.OIDC_ENABLED,
+    }

coulomb_social/apps/core/urls.py

@@ -0,0 +1,10 @@
+from django.urls import path
+
+from . import views
+
+app_name = "core"
+
+urlpatterns = [
+    path("", views.landing, name="landing"),
+    path("app/", views.app_home, name="app_home"),
+]

coulomb_social/apps/core/urls_health.py

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

coulomb_social/apps/core/views.py

@@ -0,0 +1,41 @@
+from django.contrib.auth.decorators import login_required
+from django.http import HttpRequest, HttpResponse, JsonResponse
+from django.shortcuts import render
+
+
+def landing(request: HttpRequest) -> HttpResponse:
+    if request.user.is_authenticated:
+        from django.shortcuts import redirect
+
+        return redirect("core:app_home")
+    return render(request, "core/landing.html")
+
+
+@login_required
+def app_home(request: HttpRequest) -> HttpResponse:
+    member = getattr(request.user, "member", None)
+    return render(
+        request,
+        "core/app_home.html",
+        {
+            "member": member,
+            "principal": {
+                "username": request.user.get_username(),
+                "display_name": (
+                    member.display_name
+                    if member and member.display_name
+                    else request.user.get_full_name() or request.user.get_username()
+                ),
+                "issuer": member.issuer if member else "",
+                "subject": member.subject if member else "",
+                "user_engine_user_id": (
+                    str(member.user_engine_user_id) if member else ""
+                ),
+                "tenant_id": member.tenant_id if member else "",
+            },
+        },
+    )
+
+
+def healthz(_request: HttpRequest) -> JsonResponse:
+    return JsonResponse({"status": "ok", "service": "coulomb-social"})