AtomChat

Fixed: opening the chat panel on Forge 1.20.1 turned the whole screen black (the panel was visible for an instant, then the screen went black; the game did not crash and typing/image uploads still worked). The blur pre-pass wrote GL state raw, bypassing Blaze3D's cache-gated setters ("equal cache means do not touch the driver"), so the driver and the game disagreed about the active texture unit and every later vanilla/Embeddium bind landed on the wrong one. State is now written to the driver and mirrored back into the cache, and the framebuffer, viewport and unpack pixel state are saved and restored too. Fixed: when the blur is requested but does not land this frame the panel now falls back to an opaque background instead of a 93%-opaque near-black tint that read as a full-screen black panel; a failed blur logs one throttled GL error warning and falls back. Fixed: the panel's fade layer clipped its own left edge while the open animation slid it in (32px of layer slack against a 36px slide); the layer now spans the slide. Hardened: the avatar skin read-back mirrors the texture cache too. All of the above are shared across the three builds, so Fabric and NeoForge 1.21.1 get them as well.