Fix mobile navbar compression and align header control sizing

[felixgollnhuber]

Summary

• prevent the app logo from being compressed by allowing the header layout to wrap and keeping the brand area non-shrinking
• add compact mobile labels for the language switcher, new event, and recent events controls
• standardize header control height so the language dropdown matches the recent events button
• cover the compact header behavior with an accessibility-focused component test

Testing

• pnpm verify