### System details

Omarchy version: 4.0.1

### What's wrong?

## Description

The bar clock widget uses `Qt.formatDateTime()` and `Qt.formatDate()` which internally call `QDateTime::toString()`. This function **always uses the C locale (English)** for format specifiers like `dddd` (weekday name), `MMMM` (month name), and `AP` (AM/PM marker), completely ignoring `LANG`, `LC_TIME`, and `QLocale::system()`.

This means **all non-English users** see the clock in English regardless of their system locale.

## Steps to Reproduce

1. Set system locale to any non-English language (e.g., `LANG=es_ES.UTF-8`, `LANG=de_DE.UTF-8`, `LANG=fr_FR.UTF-8`)
2. Restart the shell
3. The clock shows English day names, month names, and AM/PM format

## Expected Behavior

The clock should respect the system locale and display day/month names in the user's language.

## Actual Behavior

The clock always displays in English. For example, with `es_ES.UTF-8`:
- Shows: `Thursday, 27 August 9:51 A. M.`
- Expected: `jueves, 27 agosto 9:51 AM`

## Affected Files

Three call sites in the clock plugin:

| File | Line | Current Code |
|------|------|-------------|
| `shell/plugins/panels/clock/BarWidget.qml` | 56 | `Qt.formatDateTime(date, format)` |
| `shell/plugins/panels/clock/Panel.qml` | 315 | `Qt.formatDate(date, "MMMM d")` |
| `shell/plugins/panels/clock/Panel.qml` | 716 | `Qt.formatDate(date, "MMMM yyyy")` |

## Proposed Fix

Replace `Qt.formatDateTime()` / `Qt.formatDate()` with `Qt.locale().toString()`, which respects the system locale:

**BarWidget.qml line 55-57:**
```qml
// Before:
function formatted(date) {
    return Qt.formatDateTime(date, activeFormat.replace(/ww/g, Model.isoWeekLiteral(...)))
}

// After:
function formatted(date) {
    return Qt.locale().toString(date, activeFormat.replace(/ww/g, Model.isoWeekLiteral(...)))
}
Panel.qml line 315:
// Before:
Qt.formatDate(root.today, "MMMM d")

// After:
Qt.locale().toString(root.today, "MMMM d")
Panel.qml line 716:
// Before:
Qt.formatDate(root.viewDate, "MMMM yyyy").toUpperCase()

// After:
Qt.locale().toString(root.viewDate, "MMMM yyyy").toUpperCase()
Compatibility Note
The codebase already uses Qt.locale() elsewhere (e.g., Panel.qml line 66 for firstDayOfWeek, SpeedTestOverlay.qml for number formatting), so this fix is consistent with existing patterns. The Model.js file is explicitly locale-free and is not affected.
Environment
- Omarchy version: 4.0.1
- Qt version: 6.x
- Example locales tested: es_ES.UTF-8, es_CO.UTF-8