WSL remote sessions can time out or show stale Files and Changes state for large repositories

Description

When a Copilot remote session uses an existing large Git repository inside WSL, repository initialization and UI state can fail or become stale.

Steps to reproduce

1. Open a large existing Git repository inside WSL.
2. Start a Copilot remote session using that checkout.
3. Open the Files or Changes panel.
4. Create or modify a file.

Actual behavior

• Session startup may time out during recursive filesystem watching.
• The Files panel may fail to populate.
• Branch information or uncommitted changes may be missing.
• The Changes panel can remain empty after its initial repository scan times out.
• Later filesystem changes may not refresh the displayed state.

Expected behavior

• Remote sessions should work directly with existing WSL checkouts.
• Startup should not require enumerating the entire repository when only configuration files need monitoring.
• Files, branch information, and Git changes should load asynchronously and refresh reliably.
• Slow initial Git operations should not cause an empty state to be cached permanently.
• Users should not need a separate clone or worktree as a workaround.

Suggested improvements

• Limit configuration-file watchers to the relevant directories.
• Avoid synchronous recursive traversal during session startup.
• Make changeset calculation asynchronous and tolerant of slow Git operations.
• Retry or refresh after an initial timeout.
• Surface diagnostics when filesystem watching or Git status exceeds a timeout.

Nell’issue non sono indicati file sorgente né test. Inizia riproducendo il timeout con un repository Git di grandi dimensioni in WSL, quindi traccia l’avvio della sessione remota, il monitoraggio del filesystem e l’inizializzazione di Changes; il lavoro è completato quando Files, i dati del branch e le modifiche Git vengono caricati e aggiornati in modo affidabile senza richiedere un clone o un worktree separato.