fix: add UTF-8 BOM to CSV for Excel compatibility

[MoshiLL]

PR Title

fix: add UTF-8 BOM to CSV for Excel compatibility

Related Issue(s)

Motivation and Context

CSV files with Chinese characters display garbled text when opened in Windows Excel
because Excel doesn't recognize UTF-8 encoding by default. Adding UTF-8 BOM (EF BB BF)
solves this problem.

Summary of Changes

• Added UTF-8 BOM to auto_extracted_glossary.csv output in automatic_term_extractor.py
• Added UTF-8 BOM to auto_extracted_glossary.csv output in result_merger.py
• Added UTF-8 BOM to auto_extracted_glossary.csv output in pdf_creater.py

PR Type

• 🐛 Bug Fix

Breaking Changes

• No, this PR does not introduce breaking changes.

Testing Instructions

1. Translate a PDF with Chinese text using pdf2zh-next
2. Find the generated .glossary.csv file
3. Open the CSV in Windows Excel
4. Verify Chinese characters display correctly (not garbled)

Contributor Checklist

• I have fully read and understood the CONTRIBUTING.md guide.
• I have performed a self-review of my own code.
• My changes follow the project's code style and guidelines
• All new and existing tests passed locally with my changes
• My changes generate no new warnings or errors

---

Summary by cubic

Add a UTF-8 BOM to exported glossary CSVs so Windows Excel detects UTF-8 and displays Chinese correctly. Also save term_extractor_tracking.json and term_extractor_freq.json with UTF-8 BOM, and export glossary CSVs without the index.

^{Written for commit 3bcb1be. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="babeldoc/format/pdf/document_il/midend/automatic_term_extractor.py">

<violation number="1" location="babeldoc/format/pdf/document_il/midend/automatic_term_extractor.py:397">
P2: JSON debug artifacts are now written with UTF-8 BOM (`utf-8-sig`), reducing interoperability and potentially breaking downstream parsers expecting standard BOM-less UTF-8 JSON.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: JSON debug artifacts are now written with UTF-8 BOM (utf-8-sig), reducing interoperability and potentially breaking downstream parsers expecting standard BOM-less UTF-8 JSON.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At babeldoc/format/pdf/document_il/midend/automatic_term_extractor.py, line 397:

<comment>JSON debug artifacts are now written with UTF-8 BOM (`utf-8-sig`), reducing interoperability and potentially breaking downstream parsers expecting standard BOM-less UTF-8 JSON.</comment>

<file context>
@@ -394,14 +394,14 @@ def procress(self, doc_il: ILDocument):
             )
             logger.debug(f"save translate tracking to {path}")
-            with Path(path).open("w", encoding="utf-8") as f:
+            with Path(path).open("w", encoding="utf-8-sig") as f:
                 f.write(tracker.to_json())
 
</file context>

Suggested change

	with Path(path).open("w", encoding="utf-8-sig") as f:
	with Path(path).open("w", encoding="utf-8") as f: