Apply reference design to Astro and add screenshot storage

apps/api/tests/test_storage.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+import io
+
+import pytest
+from PIL import Image
+
+from app.storage import ScreenshotError, prepare_image
+
+
+def test_prepare_image_removes_metadata() -> None:
+    source = Image.new("RGB", (32, 24), "#12383b")
+    exif = Image.Exif()
+    exif[0x010E] = "private note"
+    raw = io.BytesIO()
+    source.save(raw, format="JPEG", exif=exif)
+
+    cleaned, extension, mime = prepare_image(raw.getvalue())
+
+    with Image.open(io.BytesIO(cleaned)) as result:
+        assert result.getexif() == {}
+        assert result.size == (32, 24)
+    assert (extension, mime) == ("jpg", "image/jpeg")
+
+
+def test_prepare_image_rejects_non_image() -> None:
+    with pytest.raises(ScreenshotError, match="valid image"):
+        prepare_image(b"not an image")