feat: complete v0.3.1 agent workflow

internal/session/store_test.go

@@ -119,6 +119,9 @@ func TestDeleteNotFound(t *testing.T) {
 
 func TestSaveRequiresID(t *testing.T) {
 	store := tempStore(t)
+	if err := store.Save(nil); err == nil {
+		t.Fatal("expected error for nil session")
+	}
 	err := store.Save(&Session{Name: "no id"})
 	if err == nil {
 		t.Fatal("expected error for empty ID")
@@ -172,3 +175,40 @@ func TestNewStoreCreatesDir(t *testing.T) {
 		t.Error("expected directory")
 	}
 }
+
+func TestStoreMaintainsSessionIndex(t *testing.T) {
+	store := tempStore(t)
+	if err := store.Save(&Session{ID: "indexed", Name: "Indexed"}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(filepath.Join(store.dir, sessionIndexFile)); err != nil {
+		t.Fatalf("index not created: %v", err)
+	}
+	metas, err := store.loadIndex()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(metas) != 1 || metas[0].ID != "indexed" {
+		t.Fatalf("index metadata = %+v", metas)
+	}
+	if err := store.Delete("indexed"); err != nil {
+		t.Fatal(err)
+	}
+	metas, err = store.loadIndex()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(metas) != 0 {
+		t.Fatalf("index after delete = %+v", metas)
+	}
+}
+
+func TestStoreRejectsUnsafeSessionID(t *testing.T) {
+	store := tempStore(t)
+	if _, err := store.Load("../outside"); err == nil {
+		t.Fatal("expected unsafe ID rejection")
+	}
+	if err := store.Save(&Session{ID: "a/b"}); err == nil {
+		t.Fatal("expected unsafe ID rejection")
+	}
+}