Add background PDF generation for published document versions

Move PDF generation from synchronous publish flow to a background polling
job. Published versions with file_id IS NULL are picked up by the job,
which generates the PDF, uploads to S3, and links the file. Export PDF
now serves stored files for published versions (with optional signature
page and watermark) and generates on the fly for drafts.

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

e2e/console/document_version_test.go

@@ -1483,3 +1483,100 @@ func TestDocumentVersion_DeleteDraft(t *testing.T) {
 		},
 	)
 }
+
+func TestDocumentVersion_ExportPDFSignatures(t *testing.T) {
+	t.Parallel()
+
+	owner := testutil.NewClient(t, testutil.RoleOwner)
+
+	t.Run(
+		"can export draft with signatures",
+		func(t *testing.T) {
+			t.Parallel()
+
+			_, docVersionID := createTestDocument(t, owner)
+
+			var result struct {
+				ExportDocumentVersionPDF struct {
+					Data string `json:"data"`
+				} `json:"exportDocumentVersionPDF"`
+			}
+
+			err := owner.Execute(`
+				mutation ExportPDF($input: ExportDocumentVersionPDFInput!) {
+					exportDocumentVersionPDF(input: $input) {
+						data
+					}
+				}
+			`, map[string]any{
+				"input": map[string]any{
+					"documentVersionId": docVersionID,
+					"withWatermark":     false,
+					"withSignatures":    true,
+				},
+			}, &result)
+			require.NoError(t, err)
+			assert.NotEmpty(t, result.ExportDocumentVersionPDF.Data)
+		},
+	)
+
+	t.Run(
+		"can export published with signatures",
+		func(t *testing.T) {
+			t.Parallel()
+
+			docID, _ := createTestDocument(t, owner)
+			approveTestDocument(t, owner, docID)
+
+			var versionResult struct {
+				Node struct {
+					Versions struct {
+						Edges []struct {
+							Node struct {
+								ID string `json:"id"`
+							} `json:"node"`
+						} `json:"edges"`
+					} `json:"versions"`
+				} `json:"node"`
+			}
+
+			err := owner.Execute(`
+				query GetVersions($id: ID!) {
+					node(id: $id) {
+						... on Document {
+							versions(first: 1, orderBy: { field: CREATED_AT, direction: DESC }) {
+								edges { node { id } }
+							}
+						}
+					}
+				}
+			`, map[string]any{"id": docID}, &versionResult)
+			require.NoError(t, err)
+			require.NotEmpty(t, versionResult.Node.Versions.Edges)
+
+			publishedVersionID := versionResult.Node.Versions.Edges[0].Node.ID
+
+			var result struct {
+				ExportDocumentVersionPDF struct {
+					Data string `json:"data"`
+				} `json:"exportDocumentVersionPDF"`
+			}
+
+			err = owner.Execute(`
+				mutation ExportPDF($input: ExportDocumentVersionPDFInput!) {
+					exportDocumentVersionPDF(input: $input) {
+						data
+					}
+				}
+			`, map[string]any{
+				"input": map[string]any{
+					"documentVersionId": publishedVersionID,
+					"withWatermark":     false,
+					"withSignatures":    true,
+				},
+			}, &result)
+			require.NoError(t, err)
+			assert.NotEmpty(t, result.ExportDocumentVersionPDF.Data)
+		},
+	)
+}