Docs: the USB kiosk, its endpoints and why the list costs a badge

Changelog, the plugin table, the three kiosk endpoints in the API inventory,
and regenerated openapi.json / PROJECT-MAP.

docs/PLUGINS.md

@@ -12,7 +12,7 @@ These plugins are in `plugins/` in this repo. Enable per site with `flask plugin
 | `computers` | Shop-floor PCs and engineering workstations | Fed by the PXE pipeline collector per [ADR-006](adr/ADR-006-collector-contract.md). |
 | `printers` | Network and shop-floor printers | Public installer map page + fleet install contract (`/api/printers/install-list`, `/pc-default`, `/install-batch`; see [PRINTER-INSTALLER.md](PRINTER-INSTALLER.md)). Optional Zabbix integration for supply tracking. Legacy `PrinterData` retiring per ADR-001. |
 | `network` | Switches, routers, access points, IDFs as locations | Asset-only; cleanest of the bundled set. |
-| `usb` | USB devices issued to shop-floor users | Lightweight checkout / check-in. |
+| `usb` | USB devices issued to shop-floor users | Lightweight checkout / check-in, self-hosted tables or an existing `cmmc_usb` database. Optional logged-out kiosk (`/usb-kiosk`, off by default) so somebody at the drive cabinet can take and return a drive without a ShopDB login, attributed to a scanned badge. |
 | `notifications` | Shop-floor notifications, recognitions, kiosk feed | Used by `ShopfloorDashboard.vue`. |
 | `measuringtools` | Metrology and inspection instruments: calipers, micrometers, thread/bore/height gages, indicators | Per [ADR-005](adr/ADR-005-equipment-vs-measuringtools.md). Calibration lifecycle with derived status. First plugin built on the matured scaffold; its walkthrough is [PLUGIN-GUIDE.md](PLUGIN-GUIDE.md). Ships `default_enabled: false`. |
 | `employees` | Read-only employee directory lookup | Backed by a separate HR database. Ships `default_enabled: false`. |