feat(advanced-search): align date display to oCIS locale

[paul43210]

Summary

• Dates in search results now use the user's oCIS preferred language setting instead of hardcoded ISO format (YYYY-MM-DD)
• formatDate() updated to accept optional locale parameter, uses toLocaleDateString() with the oCIS user locale
• Added formatDateTime() helper with 24-hour time format for future use
• Locale is read from userStore.user.preferredLanguage (oCIS account setting), falling back to browser default

Examples:

• English: "Mar 16, 2026"
• German: "16. Mär. 2026"
• French: "16 mars 2026"

Test plan

• Set oCIS user language to German → dates display in German format
• Set oCIS user language to English → dates display in English format
• Search results (list and table view) show locale-formatted dates
• Saved queries panel shows locale-formatted dates
• Photo "Date Taken" column shows locale-formatted dates

🤖 Generated with Claude Code

[mmattel]

Findings after testing:

❌ the date format shown in the input field does not change based on the locale settings
In DE, this should be yyyy/mm/dd

Note that I did a browser force reload after changing the locale on the search page.

DE:

EN:

[paul43210]

Thanks for testing Martin!

The date input fields use <input type="date">, which is a native browser control — the browser renders the display format based on its own locale, not anything we can control from JavaScript. The underlying value is always ISO format (YYYY-MM-DD) regardless of how the browser displays it. For me it shows as yyyy-mm-dd.

The locale changes in this PR affect the formatted date text elsewhere in the UI (saved query timestamps, result dates, etc.), not the native date picker inputs.

Could you point me to an existing example in oCIS/web where a date picker respects the oCIS language setting? I'd be happy to build a custom date input component that formats according to the user's oCIS language preference, but I want to make sure we're aligning with how other parts of the UI handle this — and honestly, the oCIS "Language" setting is a language preference, not a full locale (which would include regional date/number formatting). So it's not clear what the expected date format for "DE" should be — Germany uses dd.mm.yyyy, Austria uses dd.mm.yyyy too, but Switzerland might differ.

Let me know how you'd like to proceed — happy to build something if there's a clear spec to follow.

[paul43210]

To add to the above — a language setting alone isn't enough to determine date format. For example, "English" in the US uses mm/dd/yyyy, but "English" in Canada uses yyyy-mm-dd, and "English" in the UK uses dd/mm/yyyy. Same language, three different date formats.

If we want custom date pickers that respect a specific format, oCIS preferences would need a true Locale setting (e.g., en-US, en-CA, en-GB, de-DE, de-AT) rather than just a Language setting (en, de). Without that, we'd be guessing at regional formatting.

[mmattel]

Closing via #352