[Feat] (MG_Impl, MG_Backend): GL_ARB_timer_query on both backends

Implements GL timer queries end to end: a frontend query registry
(modeled on the sync module - mutex-guarded objects wrapping opaque
backend handles behind optional function pointers) serving
glGenQueries/glBeginQuery/glEndQuery(GL_TIME_ELAPSED)/glQueryCounter
(GL_TIMESTAMP)/glGetQueryObject*/glGetQueryiv with GL 3.3 error
semantics and a graceful zero-result fallback when a backend cannot
time.

DirectGLES backs spans with GL_EXT_disjoint_timer_query (context-
generation-stamped handles, bounded result waits). DirectVulkan gets a
VkTimerQueryManager: per-frame-in-flight timestamp query pools reset at
command-buffer begin (outside render passes), records harvested by
frame serial before their pool recycles, elapsed = masked tick delta x
timestampPeriod; handles are stamped with a renderer generation that
also now guards fence syncs across renderer recreation. GL_QUERY_
COUNTER_BITS reports 0 unless the live backend can actually time
(dynamic IsTimerQuerySupported hook), and a failed blocking read keeps
the handle alive so the real value stays reachable once the frame
submits.

GL_ARB_timer_query is advertised only when the device supports timing
and MOBILEGL_DISABLE_TIMERQUERY is unset - LWJGL keys Minecraft's F3
'GPU: x%' line off exactly that extension string; verified on device
(Adreno 830) on both backends.

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

MobileGL/MG_Backend/DirectVulkan/Renderer/FrameContext.cpp

@@ -97,6 +97,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VK_VERIFY(vkBeginCommandBuffer(frame.commandBuffer, &beginInfo), "BeginCommandRecording, vkBeginCommandBuffer");
 
         frame.isCommandRecording = true;
+        if (m_recordingObserver != nullptr) {
+            m_recordingObserver->OnFrameCommandRecordingBegan(frame.commandBuffer);
+        }
         return frame.commandBuffer;
     }
 
@@ -230,6 +233,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return static_cast<Uint32>(m_frames.size());
     }
 
+    void FrameContext::SetRecordingObserver(IRecordingObserver* observer) {
+        m_recordingObserver = observer;
+    }
+
     void FrameContext::AssertValidFrameIndex(Uint32 frameIndex) const {
         MOBILEGL_ASSERT(frameIndex < m_frames.size(), "FrameContext index out of range");
     }