Add user auth with JWT, switch to bun test

- User table with company_id FK, unique email, role enum
- Register/login routes with bcrypt + JWT token generation
- Auth plugin with authenticate decorator and role guards
- Login uses globally unique email (no company header needed)
- Dev-auth plugin kept as fallback when JWT_SECRET not set
- Switched from vitest to bun:test (vitest had ESM resolution
  issues with zod in Bun's module structure)
- Upgraded to zod 4
- Added Dockerfile.dev and API service to docker-compose
- 8 tests passing (health + auth)

docker-compose.dev.yml

@@ -1,4 +1,31 @@
 services:
+  api:
+    build:
+      context: .
+      dockerfile: Dockerfile.dev
+    container_name: forte-api
+    restart: unless-stopped
+    ports:
+      - "8000:8000"
+    volumes:
+      - ./packages:/app/packages
+      - ./package.json:/app/package.json
+      - /app/node_modules
+      - /app/packages/backend/node_modules
+      - /app/packages/shared/node_modules
+    environment:
+      DATABASE_URL: postgresql://forte:forte@postgres:5432/forte
+      REDIS_URL: redis://valkey:6379
+      JWT_SECRET: dev-secret-do-not-use-in-production
+      NODE_ENV: development
+      PORT: "8000"
+      HOST: "0.0.0.0"
+    depends_on:
+      postgres:
+        condition: service_healthy
+      valkey:
+        condition: service_healthy
+
   postgres:
     image: postgres:16
     container_name: forte-postgres