Epic engine: AssemblePlan is Debug (the host tests unwrap it); CI checks the nativeAssemble export

.github/workflows/build.yml

@@ -474,6 +474,7 @@ jobs:
               Java_com_droiddeck_launcher_stores_StoresNative_nativeVersion \
               Java_com_droiddeck_launcher_stores_gog_GogNative_nativeStart \
               Java_com_droiddeck_launcher_stores_epic_EpicNative_nativeStart \
+              Java_com_droiddeck_launcher_stores_epic_EpicNative_nativeAssemble \
               Java_com_droiddeck_launcher_stores_amazon_AmazonNative_nativeStart; do
             "$NM" -D --defined-only "$SO" | grep -q " ${sym}\$" \
               || { echo "::error::libdroiddeckstores.so does not export $sym"; exit 1; }

app/src/main/rust/stores/src/epic/assemble.rs

@@ -60,6 +60,7 @@ pub struct AssembleOutcome {
 
 /// The parsed plan: manifest, the files to write, and how many of them still need each chunk.
 /// Built up front so a bad index fails before anything is written.
+#[derive(Debug)]
 pub struct AssemblePlan {
     pub manifest: Manifest,
     pub install_dir: PathBuf,