diff --git a/体己/AI/ModelStore.swift b/体己/AI/ModelStore.swift
index ee13c9c..057feba 100644
--- a/体己/AI/ModelStore.swift
+++ b/体己/AI/ModelStore.swift
@@ -65,6 +65,9 @@ final class ModelStore {
     /// Demo 现场旁路:从 Bundle 拷贝预装模型(W6 才真正使用,本周占位)
     func seedFromBundle(_ kind: ModelKind) throws {
         guard let bundleURL = Bundle.main.url(forResource: kind.rawValue, withExtension: nil) else {
+            #if DEBUG
+            assertionFailure("Bundle 缺少 \(kind.rawValue),检查资源是否加入 target")
+            #endif
             return
         }
         let target = localURL(for: kind)
diff --git a/体己Tests/ModelStoreTests.swift b/体己Tests/ModelStoreTests.swift
index d1f95cf..f01be58 100644
--- a/体己Tests/ModelStoreTests.swift
+++ b/体己Tests/ModelStoreTests.swift
@@ -43,4 +43,12 @@ struct ModelStoreTests {
 
         #expect(store.totalBytes(for: .llm) == 2048)
     }
+
+    @Test func totalBytesReturnsZeroWhenFolderMissing() throws {
+        let store = try isolatedStore()
+        defer { try? FileManager.default.removeItem(at: store.rootURL) }
+
+        // 没创建任何 vl 目录
+        #expect(store.totalBytes(for: .vl) == 0)
+    }
 }