feat: add collaborative interview scheduling

Add candidate decisions, co-interviewer accounts, scheduled interview inbox and calendar views, candidate-safe meeting links, shared documents, and private live notes backed by RabbitMQ.

Extend the disposable integration environment to validate PostgreSQL migrations, seeded users, interview lifecycle behavior, and RabbitMQ fanout.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docker-compose.yml

@@ -15,6 +15,17 @@ services:
       timeout: 3s
       retries: 20
 
+  rabbitmq:
+    image: rabbitmq:4-management-alpine
+    ports:
+      - "${RABBITMQ_AMQP_PORT:-5672}:5672"
+      - "${RABBITMQ_MANAGEMENT_PORT:-15672}:15672"
+    healthcheck:
+      test: ["CMD", "rabbitmq-diagnostics", "-q", "ping"]
+      interval: 5s
+      timeout: 5s
+      retries: 20
+
   api:
     build: ./backend
     environment:
@@ -22,11 +33,14 @@ services:
       JWT_SECRET: local-development-secret-change-me-12345
       FRONTEND_URL: ${FRONTEND_URL:-http://localhost:5173}
       APP_ENV: ${APP_ENV:-development}
+      RABBITMQ_URL: amqp://guest:guest@rabbitmq:5672/
     ports:
       - "${API_PORT:-8080}:8080"
     depends_on:
       db:
         condition: service_healthy
+      rabbitmq:
+        condition: service_healthy
 
   web:
     build: ./frontend