Align Go parser backends and PDF pipeline with Python (#16676)

Ports remaining Go parser wiring and PDF backends, adds tenant-aware VLM
dispatch, aligns post-processing with Python, and adds end-to-end
pipeline coverage with a generated six-page PDF.

internal/parser/parser/pdf_parser_opendataloader_test.go

@@ -0,0 +1,152 @@
+package parser
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestPDFParser_ParseWithResult_OpenDataLoaderJSONIntegration(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost || r.URL.Path != "/file_parse" {
+			http.NotFound(w, r)
+			return
+		}
+		if got, want := r.Header.Get("Authorization"), "Bearer odl-secret"; got != want {
+			t.Errorf("Authorization = %q, want %q", got, want)
+			return
+		}
+		reader, err := r.MultipartReader()
+		if err != nil {
+			t.Errorf("MultipartReader: %v", err)
+			return
+		}
+		seenHybrid := false
+		seenSanitize := false
+		for {
+			part, err := reader.NextPart()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				t.Errorf("NextPart: %v", err)
+				return
+			}
+			switch part.FormName() {
+			case "file":
+				body, _ := io.ReadAll(part)
+				if !strings.HasPrefix(string(body), "%PDF") {
+					t.Errorf("uploaded file = %q, want PDF bytes", string(body))
+					return
+				}
+			case "hybrid":
+				body, _ := io.ReadAll(part)
+				seenHybrid = string(body) == "docling-fast"
+			case "sanitize":
+				body, _ := io.ReadAll(part)
+				seenSanitize = string(body) == "true"
+			}
+		}
+		if !seenHybrid || !seenSanitize {
+			t.Errorf("multipart fields missing: hybrid=%v sanitize=%v", seenHybrid, seenSanitize)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"json_doc":{"type":"title","content":"ODL Title","children":[{"type":"paragraph","content":"ODL Body"},{"type":"table","html":"<table><tr><td>a</td></tr></table>"}]}}`))
+	}))
+	defer server.Close()
+
+	sanitize := true
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{
+		"parse_method":             "OpenDataLoader",
+		"output_format":            "json",
+		"opendataloader_apiserver": server.URL,
+		"opendataloader_api_key":   "odl-secret",
+		"hybrid":                   "docling-fast",
+		"sanitize":                 sanitize,
+	})
+
+	res := pdf.ParseWithResult("sample.pdf", []byte("%PDF-1.4\nmock"))
+	if res.Err != nil {
+		t.Fatalf("ParseWithResult: %v", res.Err)
+	}
+	if got, want := res.OutputFormat, "json"; got != want {
+		t.Fatalf("OutputFormat = %q, want %q", got, want)
+	}
+	if len(res.JSON) < 2 {
+		t.Fatalf("JSON len = %d, want >=2", len(res.JSON))
+	}
+}
+
+func TestPDFParser_ParseWithResult_OpenDataLoaderMarkdownFallback(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/file_parse" {
+			http.NotFound(w, r)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"json_doc":null,"md_text":"# ODL Title\n\nODL Body\n"}`))
+	}))
+	defer server.Close()
+
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{
+		"parse_method":             "OpenDataLoader",
+		"output_format":            "markdown",
+		"opendataloader_apiserver": server.URL,
+	})
+	res := pdf.ParseWithResult("sample.pdf", []byte("%PDF-1.4\nmock"))
+	if res.Err != nil {
+		t.Fatalf("ParseWithResult: %v", res.Err)
+	}
+	if !strings.Contains(res.Markdown, "ODL Title") {
+		t.Fatalf("Markdown = %q, want ODL Title", res.Markdown)
+	}
+}
+
+func TestPDFParser_ParseWithResult_OpenDataLoaderRequiresAPIServer(t *testing.T) {
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{"parse_method": "OpenDataLoader"})
+	res := pdf.ParseWithResult("sample.pdf", []byte("%PDF-1.4\nmock"))
+	if res.Err == nil || !strings.Contains(res.Err.Error(), "opendataloader_apiserver") {
+		t.Fatalf("error = %v, want opendataloader_apiserver context", res.Err)
+	}
+}
+
+func TestOpenDataLoaderItems_TableCellsFallback(t *testing.T) {
+	root := map[string]any{
+		"type": "table",
+		"cells": []any{
+			map[string]any{"row": 0, "content": "a"},
+			map[string]any{"row": 0, "content": "b"},
+		},
+	}
+	items := openDataLoaderItems(root)
+	if len(items) != 1 {
+		t.Fatalf("items len = %d, want 1", len(items))
+	}
+	if got, _ := json.Marshal(items[0]); !strings.Contains(string(got), "a | b") {
+		t.Fatalf("item = %s, want row text", string(got))
+	}
+}
+
+func TestOpenDataLoaderItems_TableCellsFallbackSparseRows(t *testing.T) {
+	root := map[string]any{
+		"type": "table",
+		"cells": []any{
+			map[string]any{"row": 0, "content": "a"},
+			map[string]any{"row": 5, "content": "z"},
+		},
+	}
+	items := openDataLoaderItems(root)
+	if len(items) != 1 {
+		t.Fatalf("items len = %d, want 1", len(items))
+	}
+	if got, _ := json.Marshal(items[0]); !strings.Contains(string(got), "z") {
+		t.Fatalf("item = %s, want sparse row text", string(got))
+	}
+}