fix quattomatrix33 row/column-major mismatch

quattomatrix33 outputs column-major (comment says "opengl major") but
quatfrommatrix33 reads row-major, and the 4x4 quattomatrix also outputs
row-major. This means a quat->matrix33->quat roundtrip produces the
conjugate (inverse rotation) instead of the original quaternion.

Fix by swapping the three off-diagonal pairs so quattomatrix33 outputs
row-major, consistent with the rest of the codebase.

The only runtime caller is barycentric_svd.c which passes the result to
cn_copy_in_row_major() — previously loading the transpose, now correct.
This doesn't affect tracking results because it only needs an arbitrary
valid rotation for control point initialization.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

redist/linmath.c

@@ -546,17 +546,17 @@ inline void quattomatrix33(FLT *matrix33, const LinmathQuat qin) {
 	FLT zz = 2 * q[3] * q[3];
 	FLT zw = 2 * q[3] * q[0];
 
-	// opengl major
+	// row-major (matches quattomatrix 4x4 and quatfrommatrix33)
 	matrix33[0] = 1 - yy - zz;
-	matrix33[1] = xy + zw;
-	matrix33[2] = xz - yw;
+	matrix33[1] = xy - zw;
+	matrix33[2] = xz + yw;
 
-	matrix33[3] = xy - zw;
+	matrix33[3] = xy + zw;
 	matrix33[4] = 1 - xx - zz;
-	matrix33[5] = yz + xw;
+	matrix33[5] = yz - xw;
 
-	matrix33[6] = xz + yw;
-	matrix33[7] = yz - xw;
+	matrix33[6] = xz - yw;
+	matrix33[7] = yz + xw;
 	matrix33[8] = 1 - xx - yy;
 }