fix(stage2): preserve byte-exact prototype identities

2 files changed, 135 insertions, 21 deletions

diff --git a/crates/fparkan-assets/src/lib.rs b/crates/fparkan-assets/src/lib.rs
index 26244ee..b128822 100644
--- a/crates/fparkan-assets/src/lib.rs
+++ b/crates/fparkan-assets/src/lib.rs
@@ -570,7 +570,7 @@ pub fn prepare_mission_assets_with_repository<R: ResourceRepository>(
 #[derive(Clone, Debug, Eq, PartialEq)]
 enum PreparedVisualSignature {
     Mesh {
-        archive: String,
+        archive: Vec<u8>,
         name: Vec<u8>,
         type_id: Option<u32>,
         dependency_count: usize,
@@ -583,7 +583,7 @@ enum PreparedVisualSignature {
 fn prepared_visual_signature(proto: &EffectivePrototype) -> PreparedVisualSignature {
     match &proto.geometry {
         PrototypeGeometry::Mesh(key) => PreparedVisualSignature::Mesh {
-            archive: key.archive.as_str().to_string(),
+            archive: key.archive.identity_bytes().to_vec(),
             name: key.name.0.clone(),
             type_id: key.type_id,
             dependency_count: proto.dependencies.len(),
@@ -1160,7 +1160,7 @@ fn stable_visual_id(proto: &EffectivePrototype) -> u64 {
     match &proto.geometry {
         PrototypeGeometry::Mesh(key) => {
             1_u8.hash(&mut hasher);
-            key.archive.as_str().hash(&mut hasher);
+            key.archive.identity_bytes().hash(&mut hasher);
             key.name.0.hash(&mut hasher);
             key.type_id.hash(&mut hasher);
         }
@@ -1270,6 +1270,35 @@ mod tests {
     }
 
     #[test]
+    fn stable_visual_id_uses_archive_identity_bytes() {
+        let first = EffectivePrototype {
+            key: fparkan_prototype::PrototypeKey(resource_name(b"mesh")),
+            geometry: PrototypeGeometry::Mesh(ResourceKey {
+                archive: normalize_relative(b"DATA/\xFF.lib", PathPolicy::HostCompatible)
+                    .expect("archive"),
+                name: resource_name(b"mesh.msh"),
+                type_id: Some(0x4853_454D),
+            }),
+            source: fparkan_prototype::PrototypeSource::DirectArchive,
+            dependencies: Vec::new(),
+        };
+        let second = EffectivePrototype {
+            key: fparkan_prototype::PrototypeKey(resource_name(b"mesh")),
+            geometry: PrototypeGeometry::Mesh(ResourceKey {
+                archive: normalize_relative(b"DATA/\xFE.lib", PathPolicy::HostCompatible)
+                    .expect("archive"),
+                name: resource_name(b"mesh.msh"),
+                type_id: Some(0x4853_454D),
+            }),
+            source: fparkan_prototype::PrototypeSource::DirectArchive,
+            dependencies: Vec::new(),
+        };
+
+        assert_ne!(stable_visual_id(&first), stable_visual_id(&second));
+        assert_ne!(prepared_visual_signature(&first), prepared_visual_signature(&second));
+    }
+
+    #[test]
     #[ignore = "requires licensed corpus"]
     fn prepares_real_unit_asset_plan() {
         let root = fixture_root("IS");
diff --git a/crates/fparkan-prototype/src/lib.rs b/crates/fparkan-prototype/src/lib.rs
index 0b1e460..e85322b 100644
--- a/crates/fparkan-prototype/src/lib.rs
+++ b/crates/fparkan-prototype/src/lib.rs
@@ -640,22 +640,20 @@ fn resolve_unit_dat_prototype_requests(
     };
 
     if let Ok(unit) = decode_unit_dat(&bytes) {
-        if !unit.records.is_empty() {
-            let mut prototypes = Vec::with_capacity(unit.records.len());
-            for record in &unit.records {
-                let prototype = resolve_unit_component(repository, record)?.ok_or_else(|| {
-                    PrototypeError::Resource(ResourceError::Format(format!(
-                        "unit component {} did not resolve",
-                        String::from_utf8_lossy(cstr_bytes(&record.resource_raw))
-                    )))
-                })?;
-                prototypes.push(prototype);
-            }
-            return Ok(ResolvedPrototypeRequests {
-                expected_count: unit.records.len(),
-                prototypes,
-            });
+        let mut prototypes = Vec::with_capacity(unit.records.len());
+        for record in &unit.records {
+            let prototype = resolve_unit_component(repository, record)?.ok_or_else(|| {
+                PrototypeError::Resource(ResourceError::Format(format!(
+                    "unit component {} did not resolve",
+                    String::from_utf8_lossy(cstr_bytes(&record.resource_raw))
+                )))
+            })?;
+            prototypes.push(prototype);
         }
+        return Ok(ResolvedPrototypeRequests {
+            expected_count: unit.records.len(),
+            prototypes,
+        });
     }
 
     let binding = decode_unit_dat_binding(&bytes)?;
@@ -906,8 +904,31 @@ pub fn build_prototype_graph_report(
 }
 
 fn graph_error_edge(edge: PrototypeGraphEdge, err: &PrototypeError) -> PrototypeGraphEdge {
-    let _ = err;
-    edge
+    match err {
+        PrototypeError::Decode(_)
+        | PrototypeError::InvalidSize
+        | PrototypeError::InvalidUnitDatMagic(_)
+            if edge == PrototypeGraphEdge::MissionToUnitDat =>
+        {
+            PrototypeGraphEdge::MissionToUnitDat
+        }
+        PrototypeError::Resource(ResourceError::Format(message))
+            if message.starts_with("missing unit DAT:") =>
+        {
+            PrototypeGraphEdge::MissionToUnitDat
+        }
+        PrototypeError::Resource(ResourceError::Format(message))
+            if message.starts_with("unit component ") =>
+        {
+            PrototypeGraphEdge::UnitDatToComponent
+        }
+        PrototypeError::Resource(ResourceError::Format(message))
+            if message.contains("explicit mesh reference missing:") =>
+        {
+            PrototypeGraphEdge::PrototypeToMesh
+        }
+        _ => edge,
+    }
 }
 
 fn provenance_for_root(root_index: usize, root: &ResourceName) -> PrototypeGraphProvenance {
@@ -1582,6 +1603,69 @@ mod tests {
     }
 
     #[test]
+    fn empty_unit_dat_resolves_as_zero_component_root() {
+        let mut vfs = MemoryVfs::default();
+        let dat_path = resource_archive_path(b"UNITS/AUTO/empty.dat").expect("dat path");
+        vfs.insert(dat_path, Arc::from(vec![0_u8; 8].into_boxed_slice()));
+        let vfs = Arc::new(vfs);
+        let repo = CachedResourceRepository::new(vfs.clone());
+        let roots = [resource_name(b"UNITS/AUTO/empty.dat")];
+
+        let (graph, resolved, report) = build_prototype_graph_report(&repo, vfs.as_ref(), &roots);
+
+        assert_eq!(graph.roots.len(), 1);
+        assert!(graph.prototype_requests.is_empty());
+        assert!(resolved.is_empty());
+        assert_eq!(report.unit_reference_count, 1);
+        assert_eq!(report.unit_component_count, 0);
+        assert_eq!(report.resolved_count, 0);
+        assert!(report.failures.is_empty());
+        assert!(report.is_success());
+    }
+
+    #[test]
+    fn malformed_unit_dat_failure_is_classified_on_unit_edge() {
+        let mut vfs = MemoryVfs::default();
+        let dat_path = resource_archive_path(b"UNITS/AUTO/bad.dat").expect("dat path");
+        vfs.insert(dat_path, Arc::from([1_u8, 2, 3].to_vec().into_boxed_slice()));
+        let vfs = Arc::new(vfs);
+        let repo = CachedResourceRepository::new(vfs.clone());
+
+        let (_graph, _resolved, report) =
+            build_prototype_graph_report(&repo, vfs.as_ref(), &[resource_name(b"UNITS/AUTO/bad.dat")]);
+
+        assert_eq!(report.failures.len(), 1);
+        assert_eq!(report.failures[0].edge, PrototypeGraphEdge::MissionToUnitDat);
+    }
+
+    #[test]
+    fn missing_unit_component_failure_is_classified_on_component_edge() {
+        let mut vfs = MemoryVfs::default();
+        let dat_path = resource_archive_path(b"UNITS/AUTO/compound.dat").expect("dat path");
+        let objects_path = resource_archive_path(b"objects.rlb").expect("objects path");
+        vfs.insert(
+            dat_path,
+            Arc::from(
+                build_unit_dat(&[(b"objects.rlb".as_slice(), b"missing_component".as_slice())])
+                    .into_boxed_slice(),
+            ),
+        );
+        vfs.insert(objects_path, Arc::from(build_nres(&[]).into_boxed_slice()));
+        let vfs = Arc::new(vfs);
+        let repo = CachedResourceRepository::new(vfs.clone());
+
+        let (_graph, _resolved, report) = build_prototype_graph_report(
+            &repo,
+            vfs.as_ref(),
+            &[resource_name(b"UNITS/AUTO/compound.dat")],
+        );
+
+        assert_eq!(report.failures.len(), 1);
+        assert_eq!(report.failures[0].edge, PrototypeGraphEdge::UnitDatToComponent);
+        assert!(report.failures[0].message.contains("missing_component"));
+    }
+
+    #[test]
     fn unit_dat_expands_components_in_order() {
         let mut vfs = MemoryVfs::default();
         let dat_path = resource_archive_path(b"UNITS/AUTO/compound.dat").expect("dat path");
@@ -1896,7 +1980,7 @@ mod tests {
         assert_eq!(report.failures[0].resource_raw, b"broken");
         assert_eq!(
             report.failures[0].edge,
-            PrototypeGraphEdge::MissionToObjectsRegistry
+            PrototypeGraphEdge::PrototypeToMesh
         );
         assert!(report.failures[0].message.contains("broken"));
         assert!(report.failures[0]
@@ -1929,6 +2013,7 @@ mod tests {
 
         assert_eq!(report.failures.len(), 1);
         assert_eq!(report.failures[0].resource_raw, b"broken");
+        assert_eq!(report.failures[0].edge, PrototypeGraphEdge::PrototypeToMesh);
         assert!(report.failures[0]
             .message
             .contains("static.rlb:missing.msh"));