Implement Entity3D.animate(), closes #242

Replaced the NotImplementedError stub with a full animation
implementation. Entity3D now supports animating: x, y, z,
world_x, world_y, world_z, rotation, rot_y, scale, scale_x,
scale_y, scale_z, sprite_index, visible.

Added Entity3D as a third target type in the Animation system
(alongside UIDrawable and UIEntity), with startEntity3D(),
applyValue(Entity3D*), and proper callback support.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/test_entity3d_animate.py

@@ -0,0 +1,94 @@
+"""Test Entity3D.animate() (issue #242)"""
+import mcrfpy
+import sys
+
+errors = []
+
+vp = mcrfpy.Viewport3D(pos=(0,0), size=(100,100))
+vp.set_grid_size(16, 16)
+
+# Test 1: Basic x animation
+e = mcrfpy.Entity3D(pos=(0,0), scale=1.0)
+vp.entities.append(e)
+start_x = e.world_pos[0]
+anim = e.animate('x', 10.0, 1.0, 'linear')
+if anim is None:
+    errors.append("animate() should return Animation object")
+for _ in range(5):
+    mcrfpy.step(0.25)
+if abs(e.world_pos[0] - 10.0) > 0.5:
+    errors.append(f"x animation: expected ~10.0, got {e.world_pos[0]}")
+
+# Test 2: Scale animation
+e2 = mcrfpy.Entity3D(pos=(0,0), scale=1.0)
+vp.entities.append(e2)
+e2.animate('scale', 5.0, 0.5, 'linear')
+for _ in range(3):
+    mcrfpy.step(0.25)
+if abs(e2.scale - 5.0) > 0.5:
+    errors.append(f"scale animation: expected ~5.0, got {e2.scale}")
+
+# Test 3: Rotation animation
+e3 = mcrfpy.Entity3D(pos=(0,0), scale=1.0)
+vp.entities.append(e3)
+e3.animate('rotation', 90.0, 0.5, 'easeInOut')
+for _ in range(3):
+    mcrfpy.step(0.25)
+if abs(e3.rotation - 90.0) > 0.5:
+    errors.append(f"rotation animation: expected ~90.0, got {e3.rotation}")
+
+# Test 4: Delta animation
+e4 = mcrfpy.Entity3D(pos=(3,3), scale=1.0)
+vp.entities.append(e4)
+start_x = e4.world_pos[0]
+e4.animate('x', 2.0, 0.5, 'linear', delta=True)
+for _ in range(3):
+    mcrfpy.step(0.25)
+expected = start_x + 2.0
+if abs(e4.world_pos[0] - expected) > 0.5:
+    errors.append(f"delta animation: expected ~{expected}, got {e4.world_pos[0]}")
+
+# Test 5: Invalid property raises ValueError
+try:
+    e.animate('nonexistent', 1.0, 1.0, 'linear')
+    errors.append("Invalid property should raise ValueError")
+except ValueError:
+    pass
+
+# Test 6: Invalid target type raises TypeError
+try:
+    e.animate('x', "not_a_number", 1.0, 'linear')
+    errors.append("String target should raise TypeError")
+except TypeError:
+    pass
+
+# Test 7: Callback
+callback_called = [False]
+def on_complete(target, prop, value):
+    callback_called[0] = True
+
+e5 = mcrfpy.Entity3D(pos=(0,0), scale=1.0)
+vp.entities.append(e5)
+e5.animate('x', 5.0, 0.25, 'linear', callback=on_complete)
+for _ in range(3):
+    mcrfpy.step(0.15)
+if not callback_called[0]:
+    errors.append("Animation callback was not called")
+
+# Test 8: Easing enum
+e6 = mcrfpy.Entity3D(pos=(0,0), scale=1.0)
+vp.entities.append(e6)
+try:
+    e6.animate('x', 5.0, 1.0, mcrfpy.Easing.EASE_IN_OUT)
+except Exception as ex:
+    errors.append(f"Easing enum should work: {ex}")
+for _ in range(5):
+    mcrfpy.step(0.25)
+
+if errors:
+    for err in errors:
+        print(f"FAIL: {err}", file=sys.stderr)
+    sys.exit(1)
+else:
+    print("PASS: Entity3D.animate() (issue #242)", file=sys.stderr)
+    sys.exit(0)