Hook success messages accumulate and stack up between prompts

Description

Hook success messages (e.g., UserPromptSubmit hook success: Success) are accumulating and stacking up with each new prompt instead of being cleared. After 5 prompts, I see 5+ success messages displayed.

Steps to Reproduce

1. Configure a hook in settings.json (e.g., UserPromptSubmit hook)
2. Submit multiple prompts in sequence
3. Observe that success messages stack up rather than being cleared

Expected Behavior

Hook success messages should be cleared between prompts, showing only the current prompt's hook status.

Actual Behavior

Success messages accumulate with each prompt:

⎿  UserPromptSubmit hook succeeded: Success
⎿  UserPromptSubmit hook succeeded: Success
⎿  UserPromptSubmit hook succeeded: Success
⎿  UserPromptSubmit hook succeeded: Success
⎿  UserPromptSubmit hook succeeded: Success

Configuration

Hook configured in ~/.claude/settings.json:

"UserPromptSubmit": [
  {
    "hooks": [
      {
        "type": "command",
        "command": "bun /Users/marek/src/claude-config/scripts/observe-user-style.ts"
      }
    ]
  }
]

The hook script correctly returns JSON { continue: true } on success. The accumulation appears to be a Claude Code display issue, not a hook script issue.

Environment

• Platform: macOS (Darwin 25.0.0)
• Claude Code version: Latest