v0.179.0: Sandbox and macOS hardening, plus mission, dictation, and app UI fixes

- Sandbox hardening - Strengthened isolation of processes running inside the command sandbox
- macOS hardening - Hardened macOS releases against code injection

Bug fixes

- Mission approvals - The mission proposal body now renders once during approval instead of repeating
- Capacity errors - The CLI now backs off gracefully when a model is temporarily at capacity and no alternative is available
- Voice dictation - Long voice dictations are no longer cut off (app)
- Visualization flicker - Streamed visualizations no longer flicker while rendering (app)
- Autonomy chip - The autonomy chip in the composer now keeps a fixed width (app)
- GitHub Enterprise Server repositories - Repository lists are now correctly scoped to your organization (app)