fix(auth): delete the Kratos identity on account deletion

Account deletion removed all local data but left the Ory Kratos
identity intact — an orphaned identity that can still authenticate.
Close the gap:

- kratos.Client gains the admin API: NewClient(publicURL, adminURL)
  and DeleteIdentity (DELETE /admin/identities/{id}; a 404 is treated
  as success so a retry after a partial failure is idempotent).
- AuthService.DeleteAccount deletes the Kratos identity FIRST; if that
  call fails it aborts before touching local data, so the operation is
  retryable rather than partially applied.
- KRATOS_ADMIN_URL config (default http://kratos:4434) + router wiring.
- kratos NetworkPolicy split: the api pods may now reach the admin API
  :4434 (Traefik still reaches only the public API :4433).
- kratos CORS: allow_credentials + OPTIONS so the web browser flows
  (ory_kratos_session cookie) work; origins stay an explicit allowlist.
- Regression tests: identity teardown happens, and a Kratos failure
  aborts the deletion instead of orphaning local data.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

deploy-k3s/manifests/kratos/kratos.yaml

@@ -127,9 +127,10 @@ spec:
       port: 4434
       targetPort: 4434
 ---
-# Ingress to Kratos: Traefik (the auth.myhoneydue.com IngressRoute) and the
-# honeyDue api pods (session whoami) may reach the public API :4433. The
-# admin API :4434 takes no cluster ingress — it is reachable only in-pod.
+# Ingress to Kratos. Traefik (the auth.myhoneydue.com IngressRoute) reaches
+# only the public API :4433. The honeyDue api pods reach the public API :4433
+# (session whoami) AND the admin API :4434 (identity deletion on account
+# close). The admin API :4434 takes no other cluster ingress.
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:
@@ -142,16 +143,24 @@ spec:
   policyTypes:
     - Ingress
   ingress:
+    # Traefik ingress controller -> public API only.
     - from:
         - namespaceSelector:
             matchLabels:
               kubernetes.io/metadata.name: kube-system
+      ports:
+        - port: 4433
+          protocol: TCP
+    # honeyDue api pods -> public API (whoami) + admin API (identity deletion).
+    - from:
         - podSelector:
             matchLabels:
               app.kubernetes.io/name: api
       ports:
         - port: 4433
           protocol: TCP
+        - port: 4434
+          protocol: TCP
 ---
 # Kratos egress: DNS, the Neon Postgres database, SMTP, and HTTPS to the
 # OIDC providers (Apple/Google token + JWKS endpoints).