feat(db): перевести хранилище с SQLite на PostgreSQL

При старте backend накатывает схему PostgreSQL 18 и, если база пустая, один раз импортирует mikrotik.db с тома. Повторный старт не копирует данные. Бэкап в UI идёт через pg_dump.

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/docker-compose.postgres.yml

@@ -0,0 +1,50 @@
+# Local PostgreSQL 18 for MikrotikManager (dev / ETL dry-run).
+#   copy env.postgres.example → deploy/.env.postgres
+#   docker compose -f deploy/docker-compose.postgres.yml --env-file deploy/.env.postgres up -d
+
+services:
+  postgres:
+    image: ${POSTGRES_IMAGE_TAG:-postgres:18-alpine}
+    container_name: mmapp-postgres
+    restart: unless-stopped
+    shm_size: "256mb"
+    environment:
+      POSTGRES_USER: mmapp
+      POSTGRES_DB: mmapp
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD in .env}
+      POSTGRES_INITDB_ARGS: "--encoding=UTF8 --locale=C.UTF-8 --data-checksums"
+      TZ: UTC
+      PGTZ: UTC
+    command:
+      - postgres
+      - -c
+      - timezone=UTC
+      - -c
+      - listen_addresses=*
+      - -c
+      - max_connections=100
+      - -c
+      - shared_buffers=256MB
+      - -c
+      - work_mem=16MB
+      - -c
+      - maintenance_work_mem=128MB
+      - -c
+      - wal_compression=on
+    volumes:
+      - mmapp-pgdata:/var/lib/postgresql/data
+    ports:
+      - "127.0.0.1:${POSTGRES_PORT:-5432}:5432"
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U mmapp -d mmapp"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+volumes:
+  mmapp-pgdata: