Add NoClimb climb filter and kill-plane rescue to player controller

Two player-controller additions:

NoClimb: colliders tagged "NoClimb" are now invisible to wall-climb and
ceiling-grab. The grab detector (OnControllerColliderHit) and all three
climb probes (ProbeWall, ProbeCeiling, WallInFront) skip them, so such a
surface still blocks the capsule physically but can never be grabbed,
re-probed onto, or treated as a ceiling. WalkableGroundBelow is left
untouched (it only accepts walkable ground). The tag is read from a
serialized field (default "NoClimb"); an empty tag disables the check.

Rescue: a kill-plane fail-safe. The owner captures its spawn point on the
first Update frame (after OnNetworkSpawn's ring offset has landed) and,
if it falls below rescueMinY (-100), teleports back there with all
momentum cleared, toggling the CharacterController around the write like
PlaceOnSpawnRing. Owner-only; the authoritative NetworkTransform
replicates the reset. Runs ahead of the control gate so it rescues in any
mode.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Prefabs/Player.prefab

@@ -126,6 +126,7 @@ MonoBehaviour:
   gravity: -14.715
   groundedStickVelocity: -2
   fallAnimationSpeed: 0.1
+  rescueMinY: -100
   slideDownSteepSlopes: 1
   slideAcceleration: 20
   maxSlideSpeed: 8
@@ -144,6 +145,7 @@ MonoBehaviour:
   wallExitGrace: 0.15
   ceilingGrabDistance: 0.02
   wallTopOutBoost: 0.3
+  noClimbTag: NoClimb
   cameraOrbit: {fileID: 0}
   meshOffsetTarget: {fileID: 0}
   cameraTarget: {fileID: 4348940595172967010}