GL SSAO pass leaves units 0/1/2 bound to GBuffer attachments: genuine framebuffer feedback loop #159

src/Graphics/OpenGL/OpenGLRenderer.cpp:1356-1359, :137; assets/shaders/gbuffer_gl.frag:21-22

ExecuteSSAOPass exits with texture units 0, 1 and 2 still bound to m_gbufferDepth,
m_gbufferNormalRough and the SSAO noise texture (:1356-1359). Nothing unbinds them.

The next frame, BeginRender binds m_gbufferFBO (:137): for which m_gbufferDepth and
m_gbufferNormalRough are live attachments. A texture simultaneously bound for sampling and attached for
writing is a framebuffer feedback loop: undefined values per the GL spec, and on some drivers a hang.

Compounding it, gbuffer_gl.frag:21-22 declares units 0/1 as diffuseTexture / normalTexture: so the
geometry pass samples the depth and normal-roughness buffers as if they were material maps.

Severity: corruption (undefined behavior + wrong sampling).

Found by a full audit of the graphics layer. Assessed severity: corruption.