Session disappeared from sidebar + sidebar language switched from Japanese to English (Desktop app)

Summary

A session in the desktop app's left sidebar disappeared, and around the
same time the sidebar UI language switched from Japanese to English
without me changing any setting.

Environment

• Client: Claude Code Desktop app
• OS: Windows 11 Home (10.0.26200)

What happened

• I had an active session (working on a Google Apps Script app that

calls the Gemini API) with a title referencing "AI大喜利" (AI Ogiri).

• At some point I noticed the session was no longer listed in the left

sidebar (checked both active and archived lists via session
management tools — no trace found).

• Around the same time, the sidebar language changed from Japanese to

English, which I had not changed manually.

• Evidence the session was real: a Code.gs file it had generated was

still present in %TEMP%, so the work existed but the session
history/listing is gone.

Expected behavior

• Sessions should persist in the sidebar (or archive) until explicitly

deleted by the user.

• UI language should not change without explicit user action.

Suspicion

Both symptoms occurring together suggests a local
settings/storage reset (sidebar language and session list are likely
stored in the same local state), rather than two unrelated bugs.

Additional context

Not reliably reproducible; reporting in case others hit the same
local-storage reset issue.