feat(security): add trusted proxies and abuse event cleanup

- 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.

README.md

@@ -33,6 +33,7 @@ Upload policy defaults are also configured in megabytes and can later be changed
 - `WARPBOX_SHORT_WINDOW_SECONDS=60`
 - `WARPBOX_ANONYMOUS_STORAGE_BACKEND=local`
 - `WARPBOX_USER_STORAGE_BACKEND=local`
+- `WARPBOX_TRUSTED_PROXIES=` controls whether forwarded client IP headers are accepted only from specific proxy IPs/CIDRs. See [SECURITY_PROXY.md](./SECURITY_PROXY.md).
 
 Runtime data is configured with `WARPBOX_DATA_DIR` and defaults to `./data` in the dev environment.
 The dev script resolves that path from the repository root.
@@ -74,6 +75,73 @@ The compose example also works with Podman compatible compose tools. Its data vo
 The image exposes `/health`, `/healthz`, and `/api/v1/health`. Docker and compose healthchecks
 use `/health`.
 
+## Reverse Proxy Security
+
+Warpbox uses the resolved client IP for anonymous limits, manual bans, and automatic bans. The
+default behavior trusts `X-Forwarded-For` and `X-Real-IP` so a normal Caddy reverse proxy works
+without extra setup. For hardened deployments where the app port might be reachable from more than
+one network, set `WARPBOX_TRUSTED_PROXIES` to trusted proxy IPs/CIDRs. See
+[SECURITY_PROXY.md](./SECURITY_PROXY.md) for Caddy examples and Docker/systemd notes.
+
+## Systemd
+
+Build the binary on the server, create a dedicated user, and keep runtime data outside the repo:
+
+```bash
+cd /opt/warpbox-dev/backend
+go build -o /usr/local/bin/warpbox ./cmd/warpbox
+sudo useradd --system --home /var/lib/warpbox --shell /usr/sbin/nologin warpbox
+sudo mkdir -p /var/lib/warpbox /etc/warpbox
+sudo chown -R warpbox:warpbox /var/lib/warpbox
+sudo cp /opt/warpbox-dev/.env.example /etc/warpbox/warpbox.env
+```
+
+Example `/etc/warpbox/warpbox.env` values:
+
+```env
+WARPBOX_ENV=production
+WARPBOX_ADDR=127.0.0.1:6070
+WARPBOX_BASE_URL=https://warpbox.dev
+WARPBOX_DATA_DIR=/var/lib/warpbox
+WARPBOX_STATIC_DIR=/opt/warpbox-dev/backend/static
+WARPBOX_TEMPLATE_DIR=/opt/warpbox-dev/backend/templates
+WARPBOX_TRUSTED_PROXIES=127.0.0.1,::1
+```
+
+Example `/etc/systemd/system/warpbox.service`:
+
+```ini
+[Unit]
+Description=Warpbox file sharing service
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+User=warpbox
+Group=warpbox
+EnvironmentFile=/etc/warpbox/warpbox.env
+ExecStart=/usr/local/bin/warpbox
+Restart=always
+RestartSec=5
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ReadWritePaths=/var/lib/warpbox
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Then enable it:
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable --now warpbox
+sudo systemctl status warpbox
+```
+
+Put Caddy in front of `127.0.0.1:6070` and keep the Warpbox port closed to the public internet.
+
 ## Layout
 
 - `backend/cmd/warpbox` - main application entry point.
@@ -138,6 +206,8 @@ from `examples/sharex/warpbox-anonymous.sxcu`; update `RequestURL` to match your
   user storage quota, and usage retention.
 - `/admin/users` shows storage/daily usage and lets admins set per-user storage quota overrides.
 - `/admin/storage` manages the built-in local file backend and S3-compatible bucket backends.
+- `/admin/bans` manages manual IP/CIDR bans and optional automatic bans for suspicious probes and
+  repeated login failures. Auto-ban is off by default and configured from the admin UI.
 - Upload limits now include daily bytes, daily box counts, active box counts, short-window request
   limits, max expiration days, local storage capacity in GB, and per-user policy overrides.
 - Uploaded file content, thumbnails, and private box metadata use the selected storage backend.
@@ -158,6 +228,8 @@ Warpbox keeps local runtime data under the configured data directory:
 - `data/db/warpbox.bbolt` also stores users, sessions, invites, and collections.
 - `data/db/warpbox.bbolt` stores upload policy settings and daily usage records keyed by plain IP
   for anonymous uploads and user ID for signed-in uploads.
+- `data/db/warpbox.bbolt` stores manual bans, automatic ban settings, abuse counters, and malicious
+  path rules.
 - `data/logs/{YYYY-MM-DD}.log` - JSONL logs, one event per line.
 
 ## Static Asset Policy