Enable gzip compression in nginx for RDF and JSON content types

Adds gzip_types covering application/json, SPARQL results, RDF serializations
(Turtle, RDF/XML, LD+JSON, TriG, N-Quads, N-Triples), XML, CSS, JS, and SVG.
Primarily reduces client.xsl.sef.json transfer size from ~11.8MB to ~2-3MB.

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

Author: namedgraph

docker-compose.yml

@@ -193,6 +193,24 @@ configs:
 
           client_max_body_size ${MAX_CONTENT_LENGTH:-2097152};
 
+          gzip on;
+          gzip_types
+              application/json
+              application/ld+json
+              application/rdf+xml
+              application/sparql-results+json
+              application/sparql-results+xml
+              application/trig
+              application/n-quads
+              application/n-triples
+              application/xml
+              text/turtle
+              text/css
+              text/javascript
+              application/javascript
+              image/svg+xml;
+          gzip_min_length 1024;
+
           # server with optional client cert authentication
           server {
               listen 8443 ssl;