add Global Privacy Control metadata

nginx/server.conf

@@ -103,7 +103,7 @@ server {
         gzip_static off;
     }
 
-    location ~ "\.(txt|xml)$" {
+    location ~ "\.(json|txt|xml)$" {
         include /etc/nginx/snippets/security-headers.conf;
         add_header Cache-Control "public, max-age=1800";
     }

process_static

@@ -10,6 +10,6 @@ json_reformat -m < static_tmp/manifest.webmanifest | sponge static_tmp/manifest.
 find static_tmp -name '*.css' -exec csso {} -o {} \;
 find static_tmp -name '*.html' -exec html-minifier --collapse-whitespace --process-scripts "application/ld+json" --collapse-boolean-attributes --remove-attribute-quotes --remove-comments --remove-empty-attributes --remove-redundant-attributes --remove-script-type-attributes --remove-style-link-type-attributes --sort-attributes --sort-class-name {} -o {} \;
 find static_tmp -name '*.js' -exec terser --module -cmo {} {} \;
-find static_tmp -regex '\(.+/LICENSE\|.+\.\(css\|html\|ico\|js\|svg\|txt\|webmanifest\|xml\)\)' \
+find static_tmp -regex '\(.+/LICENSE\|.+\.\(css\|html\|ico\|js\|svg\|json\|txt\|webmanifest\|xml\)\)' \
     -exec zopfli {} \; -exec touch -r {} {}.gz \; \
     -exec brotli -k {} \;

static/.well-known/gpc.json

@@ -0,0 +1 @@
+{ "gpc": true, "version": 1 }