feat(notify): add the image field and its cleanup

Popup gains image, and the store calls an injected removeImage when an
entry is dismissed, evicted, replaced or expired, so a daemon-written
PNG does not outlive its balloon. The service decides what is
daemon-owned; the store only names the path.

NewStore now takes the callback as a third parameter, so the service
wires its removeImage in (unlinking only under ImagesDir) and the
existing call sites pass nil.

1 files changed, 17 insertions, 0 deletions

diff --git a/internal/notify/files_test.go b/internal/notify/files_test.go
index b17a4f6..606b131 100644
--- a/internal/notify/files_test.go
+++ b/internal/notify/files_test.go
@@ -55,3 +55,20 @@ func TestPublishEmptyIsAnEmptyArray(t *testing.T) {
 		t.Errorf("empty queue encoded as %q, want []", data)
 	}
 }
+
+func TestWriteImage(t *testing.T) {
+	dir := t.TempDir()
+	p, err := WriteImage(dir, 7, []byte("png-bytes"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if filepath.Base(p) != "7.png" {
+		t.Fatalf("path %q", p)
+	}
+	if b, _ := os.ReadFile(p); string(b) != "png-bytes" {
+		t.Fatalf("contents %q", b)
+	}
+	if got := ImagesDir(dir); got != filepath.Join(dir, "img") {
+		t.Fatalf("ImagesDir %q", got)
+	}
+}