Add Dagster orchestration and reduce active brands in backend

.env.example

@@ -157,6 +157,16 @@ DB_PASSWORD=changeme
 # off entirely, leaving only the startup run and the manual endpoint.
 BRAND_SYNC_INTERVAL_SECONDS=300
 
+# --- Active brands (development working set) --------------------------------
+# Comma-separated. BLANK OR UNSET = every brand is active (the production
+# default). Setting it narrows the catalog, RAG, search, MCP, analytics,
+# nutrition and every Dagster asset to these brands in one place - nothing is
+# deleted, the other brand_* tables just stop being discovered.
+# Names resolve through the brand aliases, so "Tata" activates
+# brand_hindustan_unilever exactly as ingesting Tata products would.
+#ACTIVE_BRANDS=Amul,Cadbury,Hindustan Unilever
+
+
 USE_S3=true
 S3_ACCESS_KEY=your-do-spaces-key
 S3_SECRET_KEY=your-do-spaces-secret