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.cob

@@ -0,0 +1,35 @@
+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. QRCODE-TEST.
+
+       DATA DIVISION.
+       WORKING-STORAGE SECTION.
+       01 QR-PTR          USAGE POINTER.
+       01 QR-VERSION      PIC S9(9) COMP-5.
+       01 QR-WIDTH        PIC S9(9) COMP-5.
+       01 QR-DATA-PTR     USAGE POINTER.
+       01 WS-TEXT          PIC X(20) VALUE "unsandbox-qr-ok"
+                           & X"00".
+       01 WS-ZERO         PIC S9(9) COMP-5 VALUE 0.
+       01 WS-ONE          PIC S9(9) COMP-5 VALUE 1.
+       01 WS-TWO          PIC S9(9) COMP-5 VALUE 2.
+
+       PROCEDURE DIVISION.
+       MAIN-LOGIC.
+           CALL "QRcode_encodeString"
+               USING BY REFERENCE WS-TEXT
+                     BY VALUE WS-ZERO
+                     BY VALUE WS-ONE
+                     BY VALUE WS-TWO
+                     BY VALUE WS-ONE
+               RETURNING QR-PTR.
+
+           IF QR-PTR NOT = NULL
+               SET ADDRESS OF QR-VERSION TO QR-PTR
+               SET ADDRESS OF QR-WIDTH TO QR-PTR
+               DISPLAY "QR:unsandbox-qr-ok:ROWS:" QR-WIDTH
+               CALL "QRcode_free" USING BY VALUE QR-PTR
+           ELSE
+               DISPLAY "QR encode failed"
+           END-IF.
+
+           STOP RUN.