Ship MI-GAN's bare 512 generator as the panorama border filler

Sargsyan et al., ICCV 2023; MIT code and weights (models/LICENCE.md),
exported by tools/export-migan.sh at a fixed 1×4×512×512 from the
authors' checkpoint — six operator types, 28 MB, in LFS like the rest.
The package installs it beside the scene model and the APK unpacks it
with the others.

models/LICENCE.md

@@ -11,8 +11,8 @@ same script:
 
 Both come from `https://huggingface.co/Ultralytics/YOLO26`. The face weights in
 `face/` are a separate matter with a separate grant — see `face/README.md`.
-The keypoint weights in `keypoints/` are a third, and the easiest — see the
-last section.
+The keypoint weights in `keypoints/` and the border filler in `inpaint/` are
+the other two, and the easiest — see the last two sections.
 
 ## The grant
 
@@ -99,3 +99,21 @@ XFeat trains on MegaDepth, which is itself a research dataset, but the weights
 are released under the repository's licence without a data-derived
 restriction — unlike the gaze models §7 of the requirements declined, where
 the dataset licence restricts models trained on it by name.
+
+## `inpaint/` — MI-GAN, MIT
+
+| File | Source | Trained on | Used by |
+|---|---|---|---|
+| `inpaint/migan-512.onnx` | `migan_512_places2.pt` from `https://github.com/Picsart-AI-Research/MI-GAN` (Sargsyan et al., ICCV 2023) | Places2, by the authors | the panorama border fill (FR-MRG-4) |
+
+Exported by `tools/export-migan.sh`: the bare 512 generator at a fixed
+`1×4×512×512`, six operator types. The tiling, the context and the blend are
+Rust (`dr_pano::fill`).
+
+**MIT, code and weights alike** — `LICENSE` and `LICENSE-WEIGHTS` in the
+repository, both read on 2026-09-19, both the plain MIT text with no further
+grant. GPL-compatible, store-compatible, nothing to read around: the cleanest
+position of any model here. The training set is Places2, a research dataset,
+but the weights are released under the repository's licence without a
+data-derived restriction (contrast the gaze models §7 of the requirements
+declined, and the InsightFace grant of D13).