Lock rotation mode to fr (F R) — confirmed correct on device

public/js/ar/pose.js

@@ -11,16 +11,16 @@ const _m = new THREE.Matrix4();
 const _q = new THREE.Quaternion();
 
 /* Rotation frame correction. The translation is converted from POS-IT's frame to
- * the Three.js frame by F = diag(1,-1,-1) (the -t[1]/-t[2] negation). A rotation
- * must be conjugated by the SAME F to stay in one consistent frame: R' = F R F^T.
- * Applying F to translation but leaving rotation as-is (mode 'asis') puts position
- * and orientation in different frames — position tracks but orientation tumbles
- * (phone pitch leaks into world yaw/roll). Modes are runtime-switchable for on-device
- * A/B: the debug overlay cycles ROT_MODES and calls setRotMode(). */
+ * the Three.js frame by F = diag(1,-1,-1) (the -t[1]/-t[2] negation). The rotation
+ * needs a matching left-multiply by F: R' = F R. Confirmed on-device — orientation
+ * then survives phone rotation and viewing angle. (Leaving rotation as-is ('asis')
+ * puts position and orientation in different frames so pitch leaks into yaw/roll;
+ * the full conjugation F R F^T ('frf') over-corrects for this pipeline.) Modes stay
+ * runtime-switchable for future re-tuning; the debug overlay cycles ROT_MODES. */
 const F = new THREE.Matrix4().set(1,0,0,0, 0,-1,0,0, 0,0,-1,0, 0,0,0,1);
 const Ft = F.clone().transpose();
-export const ROT_MODES = ['frf', 'asis', 'fr', 'rf'];
-let rotMode = 'frf';   // F R F^T — the frame-consistent default
+export const ROT_MODES = ['fr', 'frf', 'asis', 'rf'];
+let rotMode = 'fr';   // F R — confirmed correct on-device (orientation survives rotation/angle)
 export function setRotMode(m) { if (ROT_MODES.includes(m)) rotMode = m; }
 export function getRotMode() { return rotMode; }