Advanced Character Controller Architecture in R3F and Rapier

Act as a Lead Game Engine Developer. Architect a robust, production-ready 3D character controller utilizing React Three Fiber and `@react-three/rapier`. The controller must flawlessly support complex [MOVEMENT_TYPE] logic (e.g., strafing, sprinting, analog stick inertia) applied directly to a mathematically optimal [COLLISION_SHAPE] (e.g., a Capsule) `RigidBody`. You must implement highly custom, raycast-based logic for grounded checks to prevent infinite jumping, strict slope-angle handling to prevent sliding, and a variable [JUMP_FORCE] that responds to button-hold duration. Enforce a rigid codebase structure that absolutely separates raw keyboard/gamepad input handling from the actual physics impulse application within the `useFrame` loop for maximum maintainability.