Add static nginx fragment for config.js routing

Add config-js.conf as a static nginx configuration fragment to handle
routing for the runtime-generated config.js file. This ensures the
dynamically created config.js in /tmp/config/ is properly served via
nginx's alias directive without requiring file system writes to the
read-only application root.

Signed-off-by: Shiv Verma <shverma@redhat.com>

Author: pratap0007

ui/image/config-js.conf

@@ -0,0 +1,6 @@
+# static nginx fragment file
+location = /config.js {
+    alias /tmp/config/config.js;
+    default_type application/javascript;
+    add_header Cache-Control "no-cache, no-store, must-revalidate";
+}