[Refactor] (Espryt): route every frontend read through MGB_CTX - 113 arrow sites sed'd, 9 non-arrow lines converted (the fb-slot cache keys on MGB_CTX_IDENTITY); pull build byte-identical

- P1 package B (BRIEF-P1 C.2): the four DirectGLES TUs include <MG_Pipe/PipeInputsSwitch.h> right after
  their MG_State/GLState/Core.h include (Managers.cpp after its Managers.h include) and spell every
  frontend read MGB_CTX->Accessor(...). In the pull build MGB_CTX is MG_State::pGLContext, so the
  code is the tree before this commit token for token; in the push build it is &gPipeInputs, the block
  the frontend fills at every verb boundary.
- 113 arrow occurrences on 113 lines went through the mechanical sed (DirectGLES.cpp 91, Managers.cpp 15,
  MultiDraw.cpp 5, Utils.cpp 2). The 9 non-arrow lines follow D9: Managers.cpp's five bare/compound
  guards and three ternary conditions become MGB_CTX_LIVE (UniquePtr::operator bool spelled out, so the
  pull build does not move); DirectGLES.cpp's GetFramebufferBindingSlotFast keys its static cache on
  MGB_CTX_IDENTITY (a const void* compare) instead of pGLContext.get().
- The cache refill loop dereferences MGB_CTX once into a local reference and reads the slots through it,
  instead of &MGB_CTX->GetFramebufferBindingSlot(i) per iteration as D9 spells it: a store into
  g_fbSlotCache (a pointer) may alias the unique_ptr's own pointer under clang's TBAA, so the per-iteration
  spelling re-reads pGLContext inside the loop and grows the three functions the loop is inlined into
  (SyncCurrentProgram +16, ForceBindCurrentFBO +9, BlitNamedFramebuffer +1; .text +32). Hoisting the
  dereference restores the single load and a zero .text delta.
- grep -rc pGLContext MobileGL/MG_Backend/DirectGLES reports 0 in every file; symbol_report --threshold 0
  against the 087685d1 baseline: 0 added / 0 removed / 0 resized / 0 renamed, .text +0, nm --defined-only
  set identical. The only bytes that move are __LINE__ immediates in RecordError sites after the inserted
  include line. The 8 SyncPersistentMappedRange and 3 SyncGpuWrites sites and the PipeStats AddCalls
  literals are untouched.

MobileGL/MG_Backend/DirectGLES/MultiDraw.cpp

@@ -9,6 +9,7 @@
 #include "MultiDraw.h"
 #include "Managers.h"
 #include <MG_State/GLState/Core.h>
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include <MG_Util/Metrics/PipeStats.h>
 #include <cstring>
 #include <limits>
@@ -42,14 +43,14 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
         // verbatim is already "this batch restarts nowhere".
         Uint32 RestartSentinelFor(GLenum type) {
             if (ResolveRestartSubstitution(type) != RestartSubstitutionKind::None) {
-                return MG_State::pGLContext->GetPrimitiveRestartIndex();
+                return MGB_CTX->GetPrimitiveRestartIndex();
             }
             return MG_Util::FixedRestartIndexForGLType(type);
         }
 
         Bool RestartActive() {
-            return MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::PrimitiveRestart) ||
-                   MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::PrimitiveRestartFixedIndex);
+            return MGB_CTX->IsCapabilityEnabled(CapabilityInput::PrimitiveRestart) ||
+                   MGB_CTX->IsCapabilityEnabled(CapabilityInput::PrimitiveRestartFixedIndex);
         }
 
         // Vertices per primitive for the modes whose sub-draws may be concatenated into a
@@ -84,7 +85,7 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
         Uint BoundDrawIndirectBufferId() {
             const auto& indirect =
-                MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+                MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
             if (!indirect) return 0;
             const auto* resource = BufferImpl::EnsureBufferResource(indirect);
             return resource ? resource->id : 0;
@@ -92,7 +93,7 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
         const SharedPtr<MG_State::GLState::BufferObject>& BoundIndexBuffer() {
             static const SharedPtr<MG_State::GLState::BufferObject> none;
-            const auto& vao = MG_State::pGLContext->GetBoundVertexArray();
+            const auto& vao = MGB_CTX->GetBoundVertexArray();
             if (!vao) return none;
             return vao->GetIndexBufferBindingSlot().GetBoundObject();
         }