[18.0][attachment_preview] Add Office format preview via LibreOffice conversion

[dnplkndll]

Summary

Extends attachment_preview to support DOCX, XLSX, PPTX, DOC, XLS, PPT, and ODG preview in addition to the existing PDF + ODF support.

How it works

• New HTTP endpoint: GET /attachment_preview/office_to_pdf?model=&field=&id=&filename=
• On request, converts the binary field content to PDF using LibreOffice headless (libreoffice --headless --convert-to pdf)
• Returns the PDF to ViewerJS for in-browser rendering
• Gracefully returns HTTP 503 if LibreOffice is not installed — no preview button appears for Office files on deployments without LibreOffice

Changes

File	Change
controllers/main.py	New LibreOffice conversion HTTP controller
static/src/js/utils.esm.js	OFFICE_EXTENSIONS added to canPreview(); getUrl() routes Office extensions through conversion endpoint with ?type=pdf for ViewerJS
static/src/js/web_views/fields/binary_field.esm.js	Passes filename to showPreview() so conversion endpoint receives correct extension

Requirements

• LibreOffice must be installed in the Odoo environment for Office preview to function
• No new Python dependencies (uses stdlib subprocess, tempfile)
• Existing PDF + ODF preview unaffected

Test plan

• Upload a .docx file to a record with a binary field → preview button (↗) appears
• Click preview → ViewerJS opens with converted PDF content
• Upload a .xlsx / .pptx → same behavior
• On an Odoo instance without LibreOffice → preview button does not appear for Office files (503 response causes button to stay hidden)
• Existing PDF preview unaffected
• Existing ODS/ODT preview unaffected

🤖 Generated with Claude Code