fix: clean up App component imports and function naming

[jvalentini]

This PR fixes component import issues and improves code organization in the App component.

Changes:

• Added missing component imports (Header, VoiceInput, TextInput, Settings, Output)
• Fixed Svelte 5 props destructuring in Tab component
• Renamed function for consistency (setInputMode)
• Organized imports alphabetically
• Disabled problematic biome linting rules for Svelte files

Technical Details:

• Fixed Tab component to use const instead of let for props
• Organized imports in App.svelte and Output.svelte
• Updated biome.json to disable no-unused-imports and no-unused-variables rules

This resolves runtime errors and ensures all components are properly imported and functional.