add camera rig, click-to-move locomotion, and click interaction

Camera: Cinemachine-based rig with an anchor, a state director, point-of-
interest framing, pan input, and dialogue framing volumes.

Player: click-to-move over the NavMesh, a pointer input layer, and a motion
arbiter that reconciles direct stick input with navigation-driven movement.
The pure math is isolated in NightclubArcadia.Locomotion.Math with an EditMode
suite, so the arbitration rules are testable without a scene.

Interaction: IClickInteractable plus a bridge that routes pointer clicks to it.

Supporting project settings: adds the Cinemachine package, the Interactable and
Ground tags the raycasts depend on, and NavMesh agent dimensions matched to the
player capsule (radius 0.3, height 1.8, climb 0.25).

Co-Authored-By: Claude Opus 5 <[email protected]>

NightclubArcadia/Assets/Tests/EditMode/Locomotion/MotionInputMathTests.cs

@@ -0,0 +1,64 @@
+using NightclubArcadia.Player.Math;
+using NUnit.Framework;
+using UnityEngine;
+
+namespace NightclubArcadia.Locomotion.Math.Tests
+{
+    public class MotionInputMathTests
+    {
+        [Test]
+        public void WorldToCameraRelativeInput_ZeroVelocity_ReturnsZero()
+        {
+            var result = MotionInputMath.WorldToCameraRelativeInput(Vector3.zero, 2f, 0f);
+            Assert.AreEqual(Vector2.zero, result);
+        }
+
+        [Test]
+        public void WorldToCameraRelativeInput_YawZero_PreservesForward()
+        {
+            var world = new Vector3(0f, 0f, 2f);
+            var result = MotionInputMath.WorldToCameraRelativeInput(world, 2f, 0f);
+            Assert.AreEqual(new Vector2(0f, 1f), result);
+        }
+
+        [Test]
+        public void WorldToCameraRelativeInput_Yaw90_RotatesCorrectly()
+        {
+            var world = new Vector3(0f, 0f, 2f);
+            var result = MotionInputMath.WorldToCameraRelativeInput(world, 2f, 90f);
+            Assert.That(result.x, Is.EqualTo(1f).Within(0.001f));
+            Assert.That(result.y, Is.EqualTo(0f).Within(0.001f));
+        }
+
+        [Test]
+        public void WorldToCameraRelativeInput_ClampFractionToOne()
+        {
+            var world = new Vector3(0f, 0f, 10f);
+            var result = MotionInputMath.WorldToCameraRelativeInput(world, 2f, 0f);
+            Assert.That(result.magnitude, Is.EqualTo(1f).Within(0.001f));
+        }
+
+        [Test]
+        public void WorldToCameraRelativeInput_RoundTripsThroughAtan2()
+        {
+            var world = new Vector3(1f, 0f, 2f).normalized;
+            var cameraYaw = 15f;
+            var input = MotionInputMath.WorldToCameraRelativeInput(world, 1f, cameraYaw);
+            var targetRotation = Mathf.Atan2(input.x, input.y) * Mathf.Rad2Deg + cameraYaw;
+            var reconstructed = Quaternion.Euler(0f, targetRotation, 0f) * Vector3.forward;
+            var flatWorld = new Vector3(world.x, 0f, world.z).normalized;
+
+            Assert.That(Vector3.Dot(reconstructed, flatWorld), Is.EqualTo(1f).Within(0.001f));
+        }
+
+        [Test]
+        public void ScreenDeltaToWorldPan_UsesCameraBasis()
+        {
+            var right = Vector3.right;
+            var forward = Vector3.forward;
+            var delta = new Vector2(10f, 0f);
+            var result = MotionInputMath.ScreenDeltaToWorldPan(delta, right, forward, 0.02f);
+            Assert.AreEqual(new Vector3(-0.2f, 0f, 0f), result);
+        }
+    }
+}