feat: implement global group sync button and AI error prompt generation

[4nrry]

This PR adds the following features:

1. Replicates the LP Demo's Sincronizar tudo button in the GroupView using theme-compliant variables.
2. Synchronizes all tracked child repositories concurrently using the native Tauri backend.
3. Introduces a global error catcher that lists sync failures with precise repo paths.
4. Generates an interactive Copy Prompt button for each error, which copies an instruction (tailored for AI coding agents) directly to the user's clipboard to resolve merge conflicts.