[Feat] (MG_Impl, MG_Backend): implement the integer direct state access framebuffer clears

glClearNamedFramebufferiv and glClearNamedFramebufferuiv were stubs, so a clear through
them was silently dropped and the attachment kept whatever it held. Their float siblings
were already implemented, which is what made the gap look like a rendering bug rather than
a missing entry point.

Which buffers they accept is narrower than glClearNamedFramebufferfv and differs between
the two: signed values clear COLOR or STENCIL, unsigned only COLOR (GL 4.6 core 17.4.3.1).
Only the colour buffer is indexed, so a stencil clear naming any drawbuffer other than 0 is
INVALID_VALUE rather than merely ignored, and anything else is INVALID_ENUM. Resolving the
framebuffer by name goes through the same helper the float forms use, which is what reports
INVALID_OPERATION for a name that is neither zero nor an existing framebuffer.

Both backends express them the way they already express the float forms: DirectGLES binds
the named framebuffer and forwards to glClearBuffer*, Magma queues the payload against the
named framebuffer rather than the bound one.

direct_state_access.framebuffers_clear_errors passes on both backends, and
framebuffers_clear passes on Espryt. Magma still fails that one, for a separate reason on
the materialization side rather than in these entry points.

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -5771,6 +5771,46 @@ void main() {
         QueueClearBufferPayloadForFramebuffer(*framebuffer, buffer, drawbuffer, payload);
     }
 
+    // The integer clears carry the same payload as their target-based siblings; only the
+    // destination differs, so they queue against the named framebuffer rather than the bound one.
+    void VulkanRenderer::ClearNamedFramebufferiv(
+            const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer, GLint drawbuffer,
+            const GLint* value) {
+        if (!framebuffer || value == nullptr) {
+            return;
+        }
+        ClearAttachmentPayload payload{};
+        switch (buffer) {
+            case GL_COLOR:
+                payload.mask = GL_COLOR_BUFFER_BIT;
+                payload.color = FloatVec4(static_cast<Float>(value[0]), static_cast<Float>(value[1]),
+                                          static_cast<Float>(value[2]), static_cast<Float>(value[3]));
+                break;
+            case GL_STENCIL:
+                payload.mask = GL_STENCIL_BUFFER_BIT;
+                payload.stencil = static_cast<Uint32>(std::max(value[0], 0));
+                break;
+            default:
+                break;
+        }
+        QueueClearBufferPayloadForFramebuffer(*framebuffer, buffer, drawbuffer, payload);
+    }
+
+    void VulkanRenderer::ClearNamedFramebufferuiv(
+            const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer, GLint drawbuffer,
+            const GLuint* value) {
+        if (!framebuffer || value == nullptr) {
+            return;
+        }
+        ClearAttachmentPayload payload{};
+        if (buffer == GL_COLOR) {
+            payload.mask = GL_COLOR_BUFFER_BIT;
+            payload.color = FloatVec4(static_cast<Float>(value[0]), static_cast<Float>(value[1]),
+                                      static_cast<Float>(value[2]), static_cast<Float>(value[3]));
+        }
+        QueueClearBufferPayloadForFramebuffer(*framebuffer, buffer, drawbuffer, payload);
+    }
+
     void VulkanRenderer::ClearNamedFramebufferfi(
             const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer, GLint drawbuffer,
             GLfloat depth, GLint stencil) {

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -181,6 +181,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint* value);
         void ClearNamedFramebufferfv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer,
                                      GLenum buffer, GLint drawbuffer, const GLfloat* value);
+        void ClearNamedFramebufferiv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer,
+                                     GLenum buffer, GLint drawbuffer, const GLint* value);
+        void ClearNamedFramebufferuiv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer,
+                                      GLenum buffer, GLint drawbuffer, const GLuint* value);
         void ClearNamedFramebufferfi(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer,
                                      GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil);
         void BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,