fix: race condition in StringsLocalizationDataSource.findKey causing EXC_BAD_ACCESS

[Copilot]

Fixes EXC_BAD_ACCESS crash during realtime localization updates when UILabels refresh.

Problem

StringsLocalizationDataSource.findKey(for:) accessed the thread-safe strings property twice (lines 82, 86), creating two separate dictionary snapshots. Concurrent updates via update(with:) could modify the underlying data between these accesses, causing iteration over inconsistent state.

Changes

Thread Safety Fix

• Cache strings property once per method call
• Both for-loops now iterate over same consistent snapshot
• Eliminates race condition while preserving existing concurrent queue guarantees

func findKey(for string: String) -> String? {
    // Get a consistent snapshot of strings to avoid thread safety issues
    let currentStrings = strings
    // Simple strings
    for (key, value) in currentStrings {
        if string == value { return key }
    }
    // Formated strings
    for (key, value) in currentStrings {
        // ... formatted string matching logic
    }
    return nil
}

Impact

• Minimal change: +4/-2 lines in one file
• PluralsLocalizationDataSource already follows this pattern correctly

Original prompt

Fix issue #349

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[andrii-bodnar]

fixed in #350