## Description
Fixes#5542
This PR adds support for environment variables to configure the file
upload limit, which was previously ignored.
## Changes
- **Added support for `SYSTEMFILEUPLOADLIMIT` environment variable**:
Accepts format like "100MB", "1GB", etc.
- **Added support for `SYSTEM_MAXFILESIZE` environment variable**:
Accepts number in MB (e.g., "100" for 100MB)
- **Initialize `fileUploadLimit` from environment variables**: Added
`@PostConstruct` method in `ApplicationProperties` to read env vars and
set `fileUploadLimit` if not already set in settings.yml
- **Created `MultipartConfiguration`**: New configuration class that
syncs Spring multipart settings with `fileUploadLimit` from settings.yml
or environment variables
- **Updated `application.properties`**: Added documentation about
environment variable support
## How it works
1. On startup,
`ApplicationProperties.initializeFileUploadLimitFromEnv()` checks for
`SYSTEMFILEUPLOADLIMIT` or `SYSTEM_MAXFILESIZE` environment variables
2. If found and `fileUploadLimit` is not set in settings.yml, it sets
the value
3. `MultipartConfiguration` reads the `fileUploadLimit` via
`UploadLimitService` and configures Spring multipart settings
accordingly
4. Users can also still use `SPRING_SERVLET_MULTIPART_MAX_FILE_SIZE` and
`SPRING_SERVLET_MULTIPART_MAX_REQUEST_SIZE` directly
## Testing
Set environment variables:
- `SYSTEMFILEUPLOADLIMIT=10MB` or
- `SYSTEM_MAXFILESIZE=10`
The `fileUploadLimit` in settings.yml should be populated and multipart
limits should be respected.
