Condensed timeline display option for autopilot mode

Description:

When running in autopilot mode, the agent executes many tool calls in sequence. Currently, each tool call shows:

- Description label
- Full command preview (2-3 lines)
- Output summary ("51 lines...")

Request: Add a display option for autopilot mode that collapses each tool call to just the description label, e.g.:

● Extract authorized scopes section (shell) ▸
● Extract Bitbucket repo mapping (shell) ▸
● Create REF_SCOPES.md (file) ▸

The ▸ or similar indicator would show it's expandable. Pressing Ctrl+O/Ctrl+E would still expand as today.

Why: In autopilot mode, users primarily monitor progress via descriptions, not command details. A condensed view would:

1. Show more activity on screen at once
2. Reduce visual noise during long autonomous runs
3. Make it easier to spot when the agent pauses for input

Suggested implementation:

- New config option: display.autopilotCondensed: true
- Or a /display slash command to toggle verbosity levels