Allow Documents plugin to use system LibreOffice instead of bundled LibreOfficeDev

Feature request

Allow the Codex Documents plugin / openai-primary-runtime to use a user-configured system LibreOffice executable instead of always prioritizing the bundled LibreOfficeDev runtime.

Environment

• macOS 15.7.7 arm64
• Codex Desktop App
• Documents plugin / openai-primary-runtime
• System LibreOffice: /Applications/LibreOffice.app, version 26.2.4.2
• System soffice: /opt/homebrew/bin/soffice
• Bundled Codex runtime soffice: ~/.cache/codex-runtimes/codex-primary-runtime/dependencies/bin/soffice
• Bundled LibreOffice path: ~/.cache/codex-runtimes/codex-primary-runtime/dependencies/native/libreoffice-headless/libreoffice/LibreOfficeDev.app
• Bundled LibreOffice version observed: LibreOfficeDev 26.8.0.0.alpha0

Problem

The Documents plugin currently prioritizes the bundled LibreOfficeDev.app for document rendering/conversion. On macOS, this bundled app failed at launch due to missing Homebrew dynamic libraries, producing macOS "soffice quit unexpectedly" crash reports and interrupting document processing.

Examples from the crash/runtime output:

Library not loaded: /opt/homebrew/opt/little-cms2/lib/liblcms2.2.dylib
Referenced from: .../LibreOfficeDev.app/Contents/Frameworks/libvcllo.dylib

After installing that dependency, the next missing dependency appeared:

Library not loaded: /opt/homebrew/opt/fontconfig/lib/libfontconfig.1.dylib
Referenced from: .../LibreOfficeDev.app/Contents/Frameworks/libvcllo.dylib

Installing Homebrew dependencies can work around this specific crash, but it is not ideal because the bundled alpha/dev LibreOffice still takes precedence over the user's stable system LibreOffice.

Requested behavior

Please add a supported configuration option to choose the LibreOffice executable used by the Documents plugin, for example an environment variable:

SOFFICE_PATH=/opt/homebrew/bin/soffice

or a Codex config.toml setting:

[documents]
soffice_path = "/opt/homebrew/bin/soffice"

When configured, the Documents plugin should use the specified executable for headless conversions/rendering instead of the bundled LibreOfficeDev.app.

Why this matters

System LibreOffice is the stable release installed and maintained by the user/package manager. The bundled LibreOfficeDev alpha build is harder to debug, may depend on missing Homebrew libraries, and cannot be reliably overridden without editing Codex runtime cache files, which can be overwritten by updates.