feat: add admin console, Redis broker and chaos lab for training demo

compose.yaml

@@ -1,5 +1,5 @@
-# Local development: Postgres + the app. Mirrors what Miabi wires up for you
-# (a managed Postgres attached to the app via DATABASE_URL).
+# Local development: Postgres + Redis + the app. Mirrors what Miabi wires up
+# for you (managed databases attached to the app via env vars).
 services:
   db:
     image: postgres:17-alpine
@@ -17,14 +17,22 @@ services:
     volumes:
       - db-data:/var/lib/postgresql/data
 
+  redis:
+    image: redis:7-alpine
+
   app:
     build: .
     environment:
       PORT: 8080
       DATABASE_URL: postgres://postgres:postgres@db:5432/guestbook?sslmode=disable
+      REDIS_URL: redis://redis:6379
+      ADMIN_TOKEN: ${ADMIN_TOKEN:-change-me}
+      DEBUG_ENDPOINTS: "true"
     depends_on:
       db:
         condition: service_healthy
+      redis:
+        condition: service_started
     ports:
       - "8080:8080"