rnd(M02): extract third-person camera rig

Work-Package: M02-RND-CAMERA-001

src/scenes/player/camera_collision_policy.gd

@@ -0,0 +1,15 @@
+class_name CameraCollisionPolicy
+extends RefCounted
+
+## Replaceable third-person camera-distance policy.
+## Implementations may inspect the explicit pivot/world boundary but must return
+## a distance in Godot units without mutating the rig or camera nodes.
+
+
+## Resolves the camera distance for the current pivot and requested zoom.
+## The base policy preserves the request unchanged.
+func resolve_camera_distance(
+		_camera_pivot: Node3D,
+		requested_distance_units: float
+) -> float:
+	return requested_distance_units