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/pptx_parser.go

@@ -0,0 +1,85 @@
+//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"
+	"strings"
+
+	officeOxide "github.com/yfedoseev/office_oxide/go"
+)
+
+type PPTXParser struct {
+	libType string
+}
+
+func NewPPTXParser(libType string) (*PPTXParser, error) {
+	switch libType {
+	case OfficeOxide:
+		return &PPTXParser{
+			libType: OfficeOxide,
+		}, nil
+	default:
+		return nil, fmt.Errorf("unsupported PPTX library type: %s", libType)
+	}
+}
+
+func (p *PPTXParser) String() string {
+	return "PPTXParser"
+}
+
+// ParseWithResult emits one JSON item per slide with the slide's
+// plain text. Mirrors the python parser.py:slides branch which
+// forces output_format="json" for the slide family.
+func (p *PPTXParser) ParseWithResult(filename string, data []byte) ParseResult {
+	doc, err := officeOxide.OpenFromBytes(data, "pptx")
+	if err != nil {
+		return ParseResult{Err: fmt.Errorf("pptx open: %w", err)}
+	}
+	defer doc.Close()
+
+	text, err := doc.PlainText()
+	if err != nil {
+		return ParseResult{Err: fmt.Errorf("pptx plain-text: %w", err)}
+	}
+
+	// Split on form-feed (the python TxtParser convention used by
+	// ragflow's slide parser) — each block becomes a JSON item.
+	var items []map[string]any
+	for i, raw := range strings.Split(text, "\f") {
+		trimmed := strings.TrimSpace(raw)
+		if trimmed == "" {
+			continue
+		}
+		items = append(items, map[string]any{
+			"text":         trimmed,
+			"doc_type_kwd": "text",
+			"slide_number": i + 1,
+		})
+	}
+	if items == nil {
+		items = []map[string]any{{"text": strings.TrimSpace(text), "doc_type_kwd": "text"}}
+	}
+
+	return ParseResult{
+		OutputFormat: "json",
+		File:         map[string]any{"name": filename, "format": "pptx"},
+		JSON:         items,
+	}
+}