Sit in the cockpit with hands on the wheel by default

First person already seats you in the cockpit, so hand steering belongs with it:
the stick keeps steering until a grip actually takes hold of the wheel, and
nothing else changes until it does. "yaw_pitch" becomes the default anchor for
the same reason - from the driver's seat the vehicle's own climb reads as the
ground rising, where a level horizon reads as the kart sinking away.

Both defaults move together in runtime_config.h, the fresh-config template, the
F10 menu's reset, and both launchers, which mirror the runtime's constants. The
menu's reset also puts the rotation combo back on the default rather than on
"yaw", and now covers hand steering with the other cockpit keys.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -55,8 +55,8 @@ build, without CPU readback. Menus and
 unsupported scenes appear as a head-locked virtual screen; a validated single-camera race switches
 to immersive stereo rendering. VR is opt-in and falls back to the normal desktop renderer if the
 runtime or headset is unavailable. In first person you sit in the cockpit, where the steering wheel
-or handlebar turns with your steering, and optional hand steering by heurazy lets you grab it with
-the tracked controllers and turn it. See [`OPENXR.md`](OPENXR.md) for setup, configuration, and the
+or handlebar turns with your steering, and hand steering by heurazy lets you grab it with the
+tracked controllers and turn it. See [`OPENXR.md`](OPENXR.md) for setup, configuration, and the
 current limitations.
 
 **Music ducking.**