fix(i18n): Correct German column count label rendering - #2131

Fix German column count label rendering

The German translation for column count was using ICU plural syntax:

{count, plural, one {# Spalte} other {# Spalten}}

However, the current i18n setup (react-i18next) does not support ICU formatting, causing the raw string to be displayed in the UI.

Fix

Replaced ICU syntax with standard i18next interpolation:

"{{count}} Spalten"

Since the UI only supports 2–5 columns, plural form is always correct.

Result

Column count now renders correctly in German:

• 2 Spalten
• 3 Spalten
• etc.

Before Fix -

After Fix -

Fixes #2130