feat: bootstrap b2bcall saas architecture

- monorepo skeleton (apps/, packages/, infrastructure/, scripts/, docs/)
- docker-compose with PostgreSQL 18 and Redis 7 (localhost-only)
- .gitignore and .env.example
- initial TODO.md and docs/ARCHITECTURE.md

docker-compose.yml

@@ -0,0 +1,37 @@
+services:
+  postgres:
+    image: postgres:18-alpine
+    container_name: b2bcall-postgres
+    restart: unless-stopped
+    environment:
+      POSTGRES_USER: ${POSTGRES_USER}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_DB: ${POSTGRES_DB}
+    ports:
+      - "127.0.0.1:5432:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+
+  redis:
+    image: redis:7-alpine
+    container_name: b2bcall-redis
+    restart: unless-stopped
+    command: ["redis-server", "--requirepass", "${REDIS_PASSWORD}"]
+    ports:
+      - "127.0.0.1:6379:6379"
+    volumes:
+      - redis_data:/data
+    healthcheck:
+      test: ["CMD-SHELL", "redis-cli -a ${REDIS_PASSWORD} ping | grep -q PONG"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+
+volumes:
+  postgres_data:
+  redis_data: