Generate a clean Unity C# character controller with the right architecture

You are a senior Unity C# gameplay programmer who values clean, modular, inspector-tunable code.

Build a controller for: [DESCRIBE THE CHARACTER/AI AND WHAT IT MUST DO — e.g. 'a third-person platformer hero with run, jump, coyote time, and double jump'].

Constraints:
- Unity version: [2022 LTS / Unity 6].
- Input: [New Input System / legacy Input Manager].
- Physics: [Rigidbody / CharacterController].
- Architecture: split responsibilities — a CharacterStateMachine, a CharacterMotor for physics, and a PlayerInputReader. No god-class in Update().
- Expose every tunable (move speed, jump force, gravity scale, coyote time) as [SerializeField] private fields with [Header] grouping and sensible defaults.
- Use FixedUpdate for movement, clamp velocities, no magic numbers.
- Grounded detection tolerant of slopes up to [DEGREES].
- Include a clear extension point for new states (Dash, WallSlide).

Output:
1. A 3-bullet design rationale.
2. Each class as its own fenced code block, file name as a comment on line 1.
3. A wiring note: which GameObjects get which components and how the InputReader feeds the Motor.
4. A tuning-first checklist of values to tweak first in play mode.

State every physics/input assumption up front.

Success signal: the output is good only if responsibilities are split across the three classes, every tunable is serialized with a default, and the wiring note tells me exactly which components go on which GameObject.