Proxy Hesychia finance webhooks to chat_backend so Stripe POST is not 405.

The static SPA nginx served index.html for /api/finance/webhooks/stripe/ and rejected the method. Closes #41.

inventory/group_vars/all.yml

@@ -119,6 +119,10 @@ app_catalog:
     # Document root served by nginx and written by `npm run build:<env>`.
     # {env} is replaced with the entry's env (beta/prod).
     webroot_pattern: "/var/www/{env}.chat.aimloperations/html"
+    # hesychia.ai Stripe/RevenueCat webhooks hit this vhost. Proxy the prefix
+    # to chat_backend so POST is not answered 405 by the SPA index.html.
+    api_backend: chat_backend
+    api_proxy_prefix: /api/finance/webhooks/
   chat_backend:
     type: django
     repo: "{{ git_base_url }}/ai_ml_operations/chat_backend.git"
@@ -126,6 +130,11 @@ app_catalog:
     compose_file: docker-compose.prod.yml
     web_service: web
     migrate_cmd: "uv run python manage.py migrate --noinput"
+    # Host header the static-site webhook proxy sends. Must be in Django
+    # ALLOWED_HOSTS (see chat_backend DJANGO_ALLOWED_HOSTS).
+    public_hosts:
+      prod: chatbackend.aimloperations.com
+      beta: beta.chatbackend.aimloperations.com
   monica_site:
     type: django
     repo: "{{ git_base_url }}/ai_ml_operations/monica_site.git"