fix: use plural entity type constants for queue names; fix inventory levels sync

refactor: replace hardcoded entity_type strings with constants from models.py

fix(redis): cut workers to 7 total, remove per-iteration Redis calls to reduce connection pressure

fix(redis): use correct redis.exceptions import to re-raise ConnectionError

fix(redis): increase pool max_connections to 50, add exponential backoff on ConnectionError

feat(logging): implement production-grade structured logging with JSON and rotating files

refactor(redis-queue): reduce logging verbosity in enqueue and dequeue operations

refactor(sync-worker-ms): reduce logging verbosity in worker loop and queue operations

Add DELETE operation support to sync worker

first commit