fix(homepage): validate clock widget timezones

[nasif-naseef]

Overview

• Fixed: an invalid timezone on a Clock widget threw RangeError during render and took the homepage canvas down with it
• Added: timezone validation in the Clock edit dialog, with an inline message and a disabled Save
• Updated: ClockWidget now falls back to local time for configs already stored with an unusable zone

Changes Made

• src/ui/features/homepage/clock-timezone.ts (new) — normalizeTimezone, isValidTimezone and validateClockTimezone, shared by the widget and the dialog so the check lives in one place.
• ClockEditForm.tsx — flags an unusable zone the same way FolderMetadataDialog flags a duplicate folder name: aria-invalid, border-destructive, and an inline text-destructive message.
• WidgetEditDialog.tsx — one typeId === "clock" branch: Save is disabled while the zone is unusable, handleSave guards again, and the normalized zone is what gets stored, so America/New York is saved as America/New_York instead of being rejected. No other widget form is touched.
• ClockWidget.tsx — validates before formatting, falling back to local time (and hiding the zone label) for configs saved before this change, so an existing broken homepage recovers on its own.
• en.json — one new key, homepage.invalidTimezone.
• Tests — ClockTimezone.test.tsx and WidgetEditDialogClock.test.tsx, 38 assertions covering the widget fallback, the normalizer, the inline error, and Save being blocked and then re-enabled.

Related Issues

• Related to [BUG] Clock widget crashes the homepage canvas when the timezone is not a valid IANA name Support#1238

Screenshots / Demos

Invalid zone: the field is flagged and Save is disabled, so it can no longer be stored.

A space instead of an underscore is accepted and normalized on save — no error, Save enabled.

Saved result — the widget renders the zone as America/New_York:

Before this change, that same config threw during render and took the canvas down with it:

RangeError: Invalid time zone specified: America/New York

Checklist

• Code follows project style guidelines
• Supports mobile and desktop UI/app (if applicable)
• I have read Contributing.md
• This is not a translation request. See docs

[ZacharyZcR]

Reviewed the timezone validation, persisted-config fallback, and test coverage. The focused tests, full frontend suite, type-check, lint, formatting, and diff checks all pass. No blocking changes requested.