feat(bookstack-api-jt9): implement pages export (Markdown, PDF)

Add doRaw() for non-JSON responses. Implement ExportMarkdown() and
ExportPDF() on PagesService returning raw bytes. Add tests.

pages_test.go

@@ -75,3 +75,54 @@ func TestPagesService_Get_NotFound(t *testing.T) {
 		t.Error("expected ErrNotFound")
 	}
 }
+
+func TestPagesService_ExportMarkdown(t *testing.T) {
+	c := testClient(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/pages/5/export/markdown" {
+			t.Errorf("path = %s, want /api/pages/5/export/markdown", r.URL.Path)
+		}
+		w.Header().Set("Content-Type", "text/plain")
+		w.Write([]byte("# Hello\n\nThis is markdown."))
+	})
+
+	data, err := c.Pages.ExportMarkdown(context.Background(), 5)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(data) != "# Hello\n\nThis is markdown." {
+		t.Errorf("got %q", string(data))
+	}
+}
+
+func TestPagesService_ExportPDF(t *testing.T) {
+	pdfContent := []byte("%PDF-1.4 fake content")
+	c := testClient(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/pages/5/export/pdf" {
+			t.Errorf("path = %s, want /api/pages/5/export/pdf", r.URL.Path)
+		}
+		w.Header().Set("Content-Type", "application/pdf")
+		w.Write(pdfContent)
+	})
+
+	data, err := c.Pages.ExportPDF(context.Background(), 5)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(data) != string(pdfContent) {
+		t.Errorf("got %d bytes, want %d", len(data), len(pdfContent))
+	}
+}
+
+func TestPagesService_ExportMarkdown_NotFound(t *testing.T) {
+	c := testClient(t, func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	})
+
+	_, err := c.Pages.ExportMarkdown(context.Background(), 999)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+	if !errors.Is(err, ErrNotFound) {
+		t.Error("expected ErrNotFound")
+	}
+}