v0.4.0 — prebuilt extension (no build tools needed)

Prebuilt, ready-to-load extension. Download the zip, unzip, open chrome://extensions (or brave://extensions), enable Developer mode, Load unpacked, select the unzipped local-ai-image-detector folder, click the toolbar icon and switch Detection on.

Fully offline: model and runtime included, no downloads at any point.

This release: 89.5% pooled balanced accuracy @0.65 across 6 real-photo distributions; flux-2 recall 80%; meme FPR 5.0%; scaler-proof graphic gate for charts/screenshots. Details in eval/RESULTS.md.