[Windows Store] Create/Upgrade pet fails copying bundled hatch-pet; force reinstall removes working skill

Environment

• Codex Microsoft Store package: OpenAI.Codex_26.908.9136.0_x64__2p2nqsd0c76g0
• Windows 11, build 26200, x64

Problem

Settings > Pets > Create pet fails with the Chinese toast "无法开始创建虚拟宠物" (unable to start creating a virtual pet). Restarting the app does not resolve it. The Create/Upgrade entry points force a reinstall of the bundled hatch-pet skill; this removes an already restored working skill before the package copy fails.

Reproduction

1. Launch the Store app on the affected Windows installation.
2. Click Create pet in Pets settings.
3. Observe the error toast and incomplete destination skill directory.
4. Restore the bundled skill using read/write byte streams, then click the button again: the restored files are removed and installation fails again.

Sanitized log

At 2026-09-15T08:35:26.829Z:

[electron-fetch-handler] Failed to install recommended skill
UNKNOWN: unknown error, copyfile
'C:\Program Files\WindowsApps\OpenAI.Codex_26.908.9136.0_x64__2p2nqsd0c76g0\app\resources\skills\skills\.curated\hatch-pet\agents\openai.yaml'
-> 'C:\Users\<user>\.codex\skills\hatch-pet\agents\openai.yaml'

Local verification

• The source exists, is readable, and has the Encrypted file attribute.
• Node fs.copyFileSync on that packaged source fails with UNKNOWN, errno -4094.
• Reading the same source and writing its bytes to a normal temporary file succeeds. Native copy of that plain file also succeeds, with matching SHA-256.
• All 27 bundled skill files can be restored using byte-stream read/write; each destination hash matches its source and destinations are not encrypted.
• Inspection of the installed client shows Create/Upgrade request forceReinstall=true; the installer removes the destination before recursively copying from the bundled source.

This isolates the observed failure to local packaged-resource copying, not a confirmed sign-in or model-network failure. EFS/package protection is a suspected underlying mechanism, not fully established by these checks.

Expected behavior / suggested fix

• Install the bundled skill successfully when source contents are readable, using a byte-stream fallback where needed.
• Stage and validate an installation before replacing a known-good existing skill; preserve it if copying fails.
• Surface the local installation error instead of only a generic creation toast.

Workaround and limitations

Restore the exact bundled skill via byte-stream copying and invoke hatch-pet directly, avoiding Create/Upgrade buttons. File restoration is verified; end-to-end pet generation has not yet been verified. No WindowsApps ownership/ACL changes, app patches, credential removal, or sign-out were used.

Related packaged-copy reports: #32589 and #25220. This report adds the pet-specific force-reinstall data-loss/repeated-failure path.

Only sanitized diagnostic details are included; no credentials or conversation transcript.

Start at the Create/Upgrade entry points and the installer using forceReinstall=true; inspect the Node fs.copyFileSync path for packaged hatch-pet resources. Reproduce with the Windows Store package and verify a byte-stream fallback for readable sources. Done means installation succeeds without deleting a known-good skill first, and the local error is surfaced when installation still fails.