feat(web): enable gzip in the nginx vhost

The prerendered pages are large (the dashboard bakes the full all-time
activity dataset, ~900 KB), so compress text responses on the wire. text/html
is always compressed when gzip is on; the listed gzip_types also cover the JS
bundle, CSS, SVG icons, and (via gzip_proxied any) the JSON from the /api/
upstream. The home page drops to ~90 KB on the wire. woff2 is pre-compressed
and intentionally omitted.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X7zF7Kf4JqDwa6M8Qgge9M

asset/nginx/site.conf.tmpl

@@ -15,6 +15,29 @@ server {
     root {{DOCROOT}};
     index index.html;
 
+    # Compress text responses on the wire. text/html is always compressed when
+    # gzip is on (nginx won't let it be listed in gzip_types); the prerendered
+    # pages are large — the dashboard bakes the full all-time activity dataset —
+    # so the HTML alone drops from ~900 KB to ~90 KB. gzip_proxied any also
+    # compresses the JSON from the /api/ upstream. woff2 is already compressed,
+    # so it's intentionally not listed.
+    gzip on;
+    gzip_vary on;
+    gzip_comp_level 6;
+    gzip_min_length 1024;
+    gzip_proxied any;
+    gzip_types
+        text/css
+        text/javascript
+        text/plain
+        text/xml
+        application/javascript
+        application/json
+        application/manifest+json
+        application/xml
+        image/svg+xml
+        font/ttf;
+
     location / {
         try_files $uri $uri/ /index.html;
         add_header Cache-Control "no-cache" always;