Configure cache nginx upload limit in Helm chart

The Tuist Helm chart now configures the cache nginx sidecar’s upload size limit. A new cache.nginx.clientMaxBodySize value (default 10m, matching the cache app’s module part size) sets client_max_body_size in the generated nginx config, and request buffering is disabled on the upload proxy paths so module upload parts stream through to the cache application. Self-hosted deployments should no longer see valid Remote Cache module uploads rejected by nginx with 413 errors before reaching the cache app.