chore: update SearXNG service configuration in Docker and documentation

- Updated SearXNG image version to 2026.3.13-3c1f68c59 in the Docker Compose file.
- Added port mapping for SearXNG service to allow access on a configurable port.
- Enhanced the .env.example file with comments for SearXNG configuration and usage instructions.

docker/docker-compose.dev.yml

@@ -58,7 +58,9 @@ services:
       retries: 5
 
   searxng:
-    image: searxng/searxng:2024.12.23
+    image: searxng/searxng:2026.3.13-3c1f68c59
+    ports:
+      - "${SEARXNG_PORT:-8888}:8080"
     volumes:
       - ./searxng:/etc/searxng
     environment:

surfsense_backend/.env.example

@@ -12,6 +12,11 @@ REDIS_APP_URL=redis://localhost:6379/0
 # Optional: TTL in seconds for connector indexing lock key
 # CONNECTOR_INDEXING_LOCK_TTL_SECONDS=28800
 
+# Platform Web Search (SearXNG)
+# Set this to enable built-in web search. Docker Compose sets it automatically.
+# For standalone dev: docker run -d -p 8888:8080 -v ./docker/searxng:/etc/searxng searxng/searxng:2024.12.23
+# SEARXNG_DEFAULT_HOST=http://localhost:8888
+
 #Electric(for migrations only)
 ELECTRIC_DB_USER=electric
 ELECTRIC_DB_PASSWORD=electric_password