Localize provider storage setting

[tanish19078]

Summary

• Route the Advanced pane provider storage toggle through the localization helper.
• Add English, Simplified Chinese, and Brazilian Portuguese strings for the setting title/subtitle.
• Cover the Simplified Chinese title in the preference localization smoke test.

Fixes #971

Verification

• git diff --check HEAD~1 HEAD

[steipete]

Thanks @tanish19078, this was the right fix.

I landed it on main as eef4e1f and added the maintainer changelog credit in 7c59f8e. I could not push the fixup/changelog back to this PR because the branch has maintainer edits disabled, so I recreated the patch locally and preserved your commit authorship.

Verified with:

• swift test --filter PreferencesPaneSmokeTests
• make check
• codex-review --mode branch