Input Settings: drop the pointer role choice

The hand role the pointer takes isn't something to choose by hand. The
helper still reads POINTER_ROLE (right by default) for experiments.

Tried and reverted (not committed): in gaze mode, taking the stylus role
by reconnecting. SteamVR gave the device no role at all (hint 5, role
none) and kept the dashboard laser on the held controllers, so the mouse
couldn't click either. The dashboard laser needs a hand role, and a held
Frame controller takes its hand's.

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

session/frametop.conf.example

@@ -36,7 +36,6 @@ POINTER_GAZE_MOUSE=precision # gaze mode: the left button holds back its press,
 POINTER_PRECISION_GAIN=0.5  # gaze precision (a button mapped to gaze_precision): the pointer turns this times the controller's turn
 POINTER_PRECISION_DEADZONE=0.3 # gaze precision: degrees the controller turns before the pointer does (the press's own jolt)
 POINTER_GAZE_DRAG_GAIN=1   # gaze drag (gaze_drag): the pointer turns this times the controller's turn
-POINTER_ROLE=right         # the hand role the pointer takes: right | left | stylus. A controller held in that hand takes it back (clicks stop landing)
 GAZE_TRACKER=steam         # gaze service: steam = SteamVR's eye tracker | own = our own (frame-eyes' fe-trackd, calibrated in the gaze probe with Own tracker)
 GAZE_EYE=auto              # gaze service: eye bias. auto = each eye weighted by how far off it was at your recent nudges | left | right = that eye counts twice
 HANDS_SWAP_SIDES=0         # hand tracking (hands/run.sh install): 1 = the side cameras' names are swapped, which some SteamVR restarts cause (hands/tools/check_sides.py --ring tells)