Move the head-follow cursor only after the head passes the leash

Easing the reference toward the head all the time moved the cursor on
every small head movement, so a cursor parked in a corner of the view
drifted. Now nothing moves while the head stays within the leash. Once
the head has been past it for POINTER_LEASH_DELAY (0.2 s, so a glance
out and back doesn't count), the reference eases all the way to where
you face (POINTER_LEASH_RETURN) and the cursor lands back in its place
in the view, then the leash waits again. Leaning inside the leash no
longer moves the cursor either. Leash 0 stays head-locked.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

session/frametop.conf.example

@@ -19,8 +19,9 @@ POINTER_ORIGIN_MARGIN=0.15   # the laser starts at least this far (m) in front o
 POINTER_SCENE_RADIUS=0.5   # texture-less dashboard overlays (dock, window controls): hit radius (m) around their origin
 POINTER_EDGE_REACH=0.3     # just off a panel, the cursor stays on its plane this far (m), to reach its resize edges and window controls
 POINTER_FOLLOW=0           # 1 = the cursor follows your head on a leash (a mouse button mapped to Head follow on/off toggles it)
-POINTER_LEASH_DEG=10       # head follow: the most (degrees) the cursor can lag behind your head; 0 locks it to your view
-POINTER_LEASH_RETURN=0.2   # head follow: how quickly (s) the cursor settles back to its place in your view
+POINTER_LEASH_DEG=10       # head follow: how far (degrees) your head can turn before the cursor comes along; 0 locks it to your view
+POINTER_LEASH_DELAY=0.2    # head follow: how long (s) your head has to stay past the leash, so a glance doesn't move the cursor
+POINTER_LEASH_RETURN=0.2   # head follow: once it comes along, how quickly (s) the cursor settles back to its place in your view
 POINTER_FOLLOW_REACH=70    # head follow: how far (degrees) from the middle of your view the mouse can move the cursor
 META_DASHBOARD=0   # 1 = a Meta tap on a pass-through keyboard toggles the SteamVR dashboard (pointer mode only)
 SHARE_KEYS=0       # 1 = keys of keyboards grabbed for the desktop also go to @frametop_keys, for hotkey tools (any local process can listen)