Align Go ingestion boundaries with Python (#16647)

Moves doc_id blob resolution into Parser, tightens chunker/tokenizer to
Python output_format semantics, updates extractor list handling, and
fixes real-template integration tests.

internal/parser/parser/doc_parser.go

@@ -0,0 +1,68 @@
+//go:build cgo
+
+//
+// Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package parser
+
+import (
+	"fmt"
+
+	officeOxide "github.com/yfedoseev/office_oxide/go"
+)
+
+type DOCParser struct {
+	libType string
+}
+
+func NewDOCParser(libType string) (*DOCParser, error) {
+	switch libType {
+	case OfficeOxide:
+		return &DOCParser{
+			libType: OfficeOxide,
+		}, nil
+	default:
+		return nil, fmt.Errorf("unsupported DOC library type: %s", libType)
+	}
+}
+
+func (p *DOCParser) String() string {
+	return "DOCParser"
+}
+
+// ParseWithResult captures the office_oxide PlainText output for
+// the DOC family. Python parser.py routes .doc through tika;
+// the Go side uses office_oxide which supports DOC via PlainText.
+// OutputFormat="text" — the python side falls back to text for
+// legacy DOC files since structured extraction is unreliable.
+func (p *DOCParser) ParseWithResult(filename string, data []byte) ParseResult {
+	doc, err := officeOxide.OpenFromBytes(data, "doc")
+	if err != nil {
+		return ParseResult{Err: fmt.Errorf("doc open: %w", err)}
+	}
+	defer doc.Close()
+
+	text, err := doc.PlainText()
+	if err != nil {
+		return ParseResult{Err: fmt.Errorf("doc plain-text: %w", err)}
+	}
+
+	return ParseResult{
+		OutputFormat: "text",
+		File:         map[string]any{"name": filename, "format": "doc"},
+		Text:         text,
+	}
+}