Update environment variable handling for n8n execution mode in configuration files

- Added EXECUTIONS_MODE variable to .env.example for clarity on execution settings.
- Updated docker-compose.yml to allow dynamic assignment of EXECUTIONS_MODE, defaulting to 'queue' if not set.

.env.example

@@ -175,6 +175,7 @@ RUN_N8N_IMPORT=
 # Number of n8n worker replicas (for the n8n-worker service). Defaults to 1 if unset.
 N8N_WORKER_COUNT=
 N8N_BLOCK_FILE_ACCESS_TO_N8N_FILES=true
+EXECUTIONS_MODE=queue
 
 ############
 # [optional]

docker-compose.yml

@@ -44,7 +44,7 @@ x-n8n: &service-n8n
     DB_POSTGRESDB_PASSWORD: ${POSTGRES_PASSWORD}
     DB_POSTGRESDB_USER: postgres
     DB_TYPE: postgresdb
-    EXECUTIONS_MODE: queue
+    EXECUTIONS_MODE: ${EXECUTIONS_MODE:-queue}
     LANGCHAIN_API_KEY: ${LANGCHAIN_API_KEY}
     LANGCHAIN_ENDPOINT: ${LANGCHAIN_ENDPOINT}
     LANGCHAIN_TRACING_V2: ${LANGCHAIN_TRACING_V2}