ci: fix nginx config check cp path, add R2_ENDPOINT to .env.example

- nginx-check: cp needs trailing filename when copying to a directory
- .env.example: uncomment R2_ENDPOINT as an active variable so the
  env-docs-check script detects it as documented

.env.example

@@ -23,13 +23,12 @@ S3_BUCKET=crussell
 S3_PROFILE_PICS_BUCKET=crussell-profile-pics
 AWS_REGION=eu-west-2
 
-# Prod: Uncomment and fill these for R2
+# Prod: Set R2_ENDPOINT for Cloudflare R2 (overrides S3_* vars in non-dev builds)
-# R2_ENDPOINT=https://<account-id>.r2.cloudflarestorage.com
+R2_ENDPOINT=
 # R2_ACCESS_KEY=<your-access-key>
 # R2_SECRET_KEY=<your-secret-key>
 # R2_BUCKET=crussell
 # R2_PUBLIC_URL=https://pub-<your-domain>.r2.dev
-# AWS_REGION=auto
 
 # Square Payment Gateway
 SQUARE_ACCESS_TOKEN=

.gitea/workflows/ci.yaml

@@ -771,5 +771,5 @@ jobs:
 
       - name: Validate nginx config
         run: |
-          cp $(pwd)/nginx/conf.d/default.conf /etc/nginx/conf.d/
+          cp $(pwd)/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf
           nginx -t