Checkpoint: pre-realignment working tree (Gym->GymSub repoint + SyntyWorld/PostFX re-enable, SampleScene removed, PostFX_Daylight retune, ai.assistant pkg re-added)

Baseline before the LANTERN realignment & purge (plan: one look, four scenes,
Bathynaut on the player). Gym.unity edits are operator-made in-editor.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/_Project/Rendering/PostFX_Daylight.asset

@@ -179,13 +179,13 @@ MonoBehaviour:
   active: 1
   shadows:
     m_OverrideState: 1
-    m_Value: {x: 0.92, y: 1, z: 1.05, w: -0.02}
+    m_Value: {x: 0.87619054, y: 0.952381, z: 1, w: -0.02}
   midtones:
     m_OverrideState: 1
-    m_Value: {x: 0.98, y: 1, z: 1.02, w: 0}
+    m_Value: {x: 0.9607844, y: 0.98039216, z: 1, w: 0}
   highlights:
     m_OverrideState: 1
-    m_Value: {x: 1.06, y: 1, z: 0.92, w: 0}
+    m_Value: {x: 1, y: 0.9433963, z: 0.8679246, w: 0}
   shadowsStart:
     m_OverrideState: 1
     m_Value: 0