Clean up tool output formatting in interactive mode

Fix the ugly tool output formatting in agent -i interactive mode.

Current (bad)

[run_bash] {"command": "ls -la", ...}
{"output": "total 48\ndrwxr-xr-x..."}

Desired

$ ls -la
total 48
drwxr-xr-x  5 ben users 4096 Jan 17 ...
...

Requirements

1. For bash tools: show $ <command> then the output on next lines 2. For other tools: show [tool_name] <brief summary> then output 3. Keep output concise - truncate to ~10 lines with "... (N more lines)" 4. Muted formatting - tool output should be visually secondary to LLM responses 5. Store full output for /expand command (already implemented)

Files

• Omni/Agent.hs - the interactiveMode and replLoop functions

Notes

• Don't add colors yet, just fix the text formatting
• The tool results come from runAgent - you may need to parse them
• Look at how tool output is currently captured and displayed