Raise report upload request size limits

- Configure NestJS with an explicit JSON and urlencoded body parser limit controlled by API_BODY_LIMIT.

- Set the default API body limit to 100mb for report HTML, key frames, template images, and Data URL file uploads.

- Add a matching Nginx client_max_body_size 100m limit so Docker web proxy no longer rejects large report saves first.

- Document the new request body limit in README, deployment docs, progress notes, environment example, and AGENTS context.

- Rebuild and verify Docker web/api with a large report save through the Nginx /api proxy.

nginx.conf

@@ -6,6 +6,7 @@ map $http_upgrade $connection_upgrade {
 server {
     listen 80;
     server_name localhost;
+    client_max_body_size 100m;
     root /usr/share/nginx/html;
     index index.html;