refactor(srp): remove managed frame planning hook

- derive fullscreen stage planning from pipeline render-graph support
- trim planning-only APIs from the managed SRP bridge and public surface
- update probes and tests to lock the slimmer SRP API boundary

managed/GameScripts/RenderPipelineApiProbe.cs

@@ -766,15 +766,6 @@ namespace Gameplay
                 postProcessScale);
         }
 
-        protected override void ConfigureCameraFramePlan(
-            ScriptableRenderPipelinePlanningContext context)
-        {
-            context.ClearFullscreenStage(CameraFrameStage.PostProcess);
-            context.RequestFullscreenStage(
-                CameraFrameStage.PostProcess,
-                CameraFrameColorSource.MainSceneColor,
-                false);
-        }
     }
 
     public sealed class ManagedPlannedFullscreenRenderPipelineProbeAsset
@@ -785,19 +776,6 @@ namespace Gameplay
             return new ManagedPlannedFullscreenRenderPipelineProbe();
         }
 
-        protected override void ConfigureCameraFramePlan(
-            ScriptableRenderPipelinePlanningContext context)
-        {
-            context.ClearFullscreenStage(CameraFrameStage.PostProcess);
-            context.ClearFullscreenStage(CameraFrameStage.FinalOutput);
-            context.RequestFullscreenStage(
-                CameraFrameStage.PostProcess,
-                CameraFrameColorSource.MainSceneColor,
-                true);
-            context.RequestFullscreenStage(
-                CameraFrameStage.FinalOutput,
-                CameraFrameColorSource.PostProcessColor);
-        }
     }
 
     internal sealed class ManagedCameraRequestConfiguredRendererData
@@ -877,19 +855,6 @@ namespace Gameplay
             return new ManagedRenderContextStageColorDataProbe();
         }
 
-        protected override void ConfigureCameraFramePlan(
-            ScriptableRenderPipelinePlanningContext context)
-        {
-            context.ClearFullscreenStage(CameraFrameStage.PostProcess);
-            context.ClearFullscreenStage(CameraFrameStage.FinalOutput);
-            context.RequestFullscreenStage(
-                CameraFrameStage.PostProcess,
-                CameraFrameColorSource.MainSceneColor,
-                true);
-            context.RequestFullscreenStage(
-                CameraFrameStage.FinalOutput,
-                CameraFrameColorSource.PostProcessColor);
-        }
     }
 
     public sealed class ManagedRenderPipelineProbe