Add EvoSync v3 environment scaffold

FastAPI + Celery + Redis + MariaDB stack with 6-service docker-compose.
Includes project skeleton (config, database, models, tasks, migrations)
and health endpoint with passing test.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/tasks/celery_app.py

@@ -0,0 +1,22 @@
+from celery import Celery
+
+from web.config import settings
+
+celery_app = Celery("evosync", broker=settings.REDIS_URL, backend=settings.REDIS_URL)
+
+celery_app.conf.update(
+    task_serializer="json",
+    result_serializer="json",
+    accept_content=["json"],
+    timezone="Europe/Moscow",
+    enable_utc=True,
+    task_track_started=True,
+    task_acks_late=True,
+    worker_prefetch_multiplier=1,
+    broker_connection_retry_on_startup=True,
+    task_routes={
+        "web.tasks.sync.*": {"queue": "sync"},
+        "web.tasks.health.*": {"queue": "health"},
+        "web.tasks.catalog.*": {"queue": "default"},
+    },
+)