A barcode/QR scanner is an HID "keyboard wedge" — it types the id + Enter into
whatever holds focus. Previously that only worked while the ticket <input> was
focused; a scan with focus elsewhere (or nowhere) went nowhere.
New useScanner hook (apps/web/src/lib/use-scanner.ts): a document-level keydown
listener that detects the scanner's FAST keystroke burst ended by Enter and opens
the pay/exit modal via setActiveTicket — regardless of focus. A gap > 50ms resets
the buffer, so human-paced typing with nothing focused never registers as a scan
(min length 3 guards stray Enters). Keystrokes into an input/textarea/select/
contenteditable are ignored, so the manual ticket field still works by hand. The
hook is paused while a modal is already open — a scan must not abandon an
in-progress payment; the operator finishes/closes, then scans the next car.
Verified at runtime (Playwright): a fast burst with focus on BODY opens the modal;
a second scan while the modal is open is ignored; slow (120ms) human typing does
NOT open it; the manual input submit still opens it. build+lint 14/14.
Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V
julian
3ed785c33e