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_tcadp_test.go

@@ -0,0 +1,104 @@
+package parser
+
+import (
+	"archive/zip"
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestPDFParser_ParseWithResult_TCADPJSONIntegration(t *testing.T) {
+	zipPayload := tcadpZipFixture(t)
+	var server *httptest.Server
+	server = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/reconstruct_document":
+			if got, want := r.Header.Get("Authorization"), "Bearer tcadp-secret"; got != want {
+				t.Errorf("Authorization = %q, want %q", got, want)
+				return
+			}
+			_, _ = w.Write([]byte(`{"DocumentRecognizeResultUrl":"` + server.URL + `/download.zip"}`))
+		case "/download.zip":
+			w.Header().Set("Content-Type", "application/zip")
+			_, _ = w.Write(zipPayload)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer server.Close()
+
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{
+		"parse_method":    "TCADP parser",
+		"output_format":   "json",
+		"tcadp_apiserver": server.URL,
+		"tcadp_api_key":   "tcadp-secret",
+	})
+	res := pdf.ParseWithResult("sample.pdf", []byte("%PDF-1.4\nmock"))
+	if res.Err != nil {
+		t.Fatalf("ParseWithResult: %v", res.Err)
+	}
+	if len(res.JSON) < 2 {
+		t.Fatalf("JSON len = %d, want >=2", len(res.JSON))
+	}
+}
+
+func TestPDFParser_ParseWithResult_TCADPMarkdownIntegration(t *testing.T) {
+	zipPayload := tcadpZipFixture(t)
+	var server *httptest.Server
+	server = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/reconstruct_document":
+			_, _ = w.Write([]byte(`{"DocumentRecognizeResultUrl":"` + server.URL + `/download.zip"}`))
+		case "/download.zip":
+			_, _ = w.Write(zipPayload)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer server.Close()
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{
+		"parse_method":    "TCADP parser",
+		"output_format":   "markdown",
+		"tcadp_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, "Hello TCADP") {
+		t.Fatalf("Markdown = %q, want fixture text", res.Markdown)
+	}
+}
+
+func TestPDFParser_ParseWithResult_TCADPRequiresAPIServer(t *testing.T) {
+	pdf := NewPDFParser()
+	pdf.ConfigureFromSetup(map[string]any{"parse_method": "TCADP parser"})
+	res := pdf.ParseWithResult("sample.pdf", []byte("%PDF-1.4\nmock"))
+	if res.Err == nil || !strings.Contains(res.Err.Error(), "tcadp_apiserver") {
+		t.Fatalf("error = %v, want tcadp_apiserver context", res.Err)
+	}
+}
+
+func tcadpZipFixture(t *testing.T) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	writer := zip.NewWriter(&buf)
+	f1, err := writer.Create("result.md")
+	if err != nil {
+		t.Fatalf("Create md: %v", err)
+	}
+	_, _ = f1.Write([]byte("Hello TCADP"))
+	f2, err := writer.Create("blocks.json")
+	if err != nil {
+		t.Fatalf("Create json: %v", err)
+	}
+	_, _ = f2.Write([]byte(`[{"type":"table","table_data":{"rows":[["a","b"]]}}]`))
+	if err := writer.Close(); err != nil {
+		t.Fatalf("Close zip: %v", err)
+	}
+	return buf.Bytes()
+}