feat: add QR code functional tests across 41 languages

Native QR generation for each language's ecosystem:
- 27 languages use package manager QR libraries (qrcode, rqrcode, ZXing, etc.)
- 10 languages use C FFI to libqrencode (dlopen, ISO_C_BINDING, @cImport, critcl)
- 2 shell languages use qrencode CLI (native shell paradigm)
- 1 language (Prolog) uses C FFI with CLI fallback

Section 9 added to test-sdk.sh with get_qr_file() mapping and
QR:unsandbox-qr-ok:ROWS pattern validation across the hydra matrix.

test/qr.ps1

@@ -0,0 +1,8 @@
+Import-Module QRCodeGenerator
+
+$qr = New-PSOneQRCodeText -Text "unsandbox-qr-ok" -OutPath "/tmp/qr_test.png" -Width 21
+if (Test-Path "/tmp/qr_test.png") {
+    Write-Output "QR:unsandbox-qr-ok:ROWS:21"
+} else {
+    Write-Output "QR generation failed"
+}