Replace manual IP logging using `uploadClientIP(r)` with the
`withRequestLogAttrs` helper function in `manage.go`. This simplifies
the log statements and standardizes the extraction of request-related
attributes.
- Update user policy and user update handlers to accept -1 as an unlimited value for MaxDays, DailyBoxes, ActiveBoxes, and ShortWindowRequests.
- Introduce `optionalIntAllowUnlimited` helper and update `optionalMBAllowZero` to support -1.
- Use `boxExpiryLabel` helper across admin, dashboard, and download handlers to properly format expiration dates, supporting boxes that never expire.
- Add `WARPBOX_TRUSTED_PROXIES` configuration to restrict accepted forwarded client IP headers to specific proxy IPs/CIDRs, securing client IP resolution.
- Integrate `BanService` into the background cleanup job to automatically purge expired abuse and ban evidence events.
- Update documentation with reverse proxy security guidelines and a production systemd deployment guide.
- Add environment variables to configure anonymous uploads, daily upload caps, and default user storage limits.
- Update config loader to parse and validate the new settings.
- Implement backend logic to track daily usage and active storage per user.
- Update README and `.env.example` to document the new settings and admin panels.
- Add an API documentation page with curl and ShareX examples.
- Implement a dynamic ShareX configuration endpoint (`/api/v1/sharex/warpbox-anonymous.sxcu`) that generates a `.sxcu` file pre-configured with the instance's base URL.
- Update anonymous uploads to return a private management link (`manageUrl`) and a deletion link (`deleteUrl`) in JSON responses.
- Update README with details on Stage 3 Anonymous Integrations.
- Add styling for the new API documentation view and management details.