Add QR code capture (#6705)

Select a screen region and decode the QR code in it to the clipboard, so
an otpauth:// setup code shown on screen no longer needs a phone.

The decoded value is only ever placed on the clipboard, and marked
sensitive so clipboard history skips it. Decoding is restricted to QR so
a stray barcode elsewhere on screen can't take the clipboard instead.

Co-authored-by: Hlib Kanunnikov <hlibwondertan@gmail.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

migrations/1786447584.sh

@@ -0,0 +1,3 @@
+echo "Install QR code scanning support"
+
+omarchy-pkg-add zbar