[app/skills] Office skill metadata advertises unsupported legacy .ppt and .xls files

Installed versions

• Codex Desktop app: 26.810.41047, bundle 6570, macOS arm64
• Presentations and Spreadsheets skill bundles: 26.813.12317

Reproduction

The bundled Presentations plugin description explicitly activates for .ppt and .pptx. The skill workflow, however, is a PPTX workflow, and its renderer accepts only:

.pptx, .ppsx, .potx, .pptm, .ppsm, .potm

There is no legacy .ppt import or conversion route in the installed skill.

The bundled Spreadsheets skill frontmatter explicitly activates for .xlsx, .xls, .csv, and .tsv, but the body only lists .xlsx, .csv, .tsv. The documented artifact API exposes SpreadsheetFile.importXlsx and exportXlsx; no legacy .xls import or conversion route is documented or bundled.

Therefore a request using one of the explicitly advertised legacy extensions can select a skill with no supported operating path for that file type.

Expected behavior

Skill trigger metadata should advertise only file formats that have a documented, testable route, or it should route legacy formats through an explicit converter with a clear stop/failure contract.

Actual behavior

.ppt and .xls are advertised as supported triggers, while the operational workflows and bundled helpers support OOXML .pptx/.xlsx instead.

Proposed narrow fix

Either remove .ppt and .xls from the plugin and skill descriptions, or add an explicit, dependency-declared conversion route before entering the PPTX/XLSX workflow. The narrowest safe fix is to stop advertising formats that are not handled.

Acceptance test

Add extension-routing fixtures that enumerate every advertised extension and require exactly one of:

1. A supported import/render/export path.
2. An explicit converter with deterministic failure behavior.
3. A clear unsupported-format response without entering authoring.

The metadata and fixture matrix should remain generated or checked together.

This report does not request editing the managed cache; the fix belongs in the upstream bundle/package source.