Excessive iTerm2 notifications during active turns on Opus 4.5 (v2.0.53)

Description

After updating to Claude Code 2.0.53 with Opus 4.5 model, iTerm2 notifications are firing excessively - even during active turns while Claude is processing, not just during idle periods.

Expected Behavior

Per the changelog for v2.0.37 ("Fixed how idleness is computed for notifications"), notifications should only trigger after 60+ seconds of idleness when Claude is waiting for user input.

Actual Behavior

Notifications fire continuously during active sessions, including while Claude is mid-turn executing tools and generating responses.

Environment

• Claude Code version: 2.0.53
• Model: Opus 4.5 (claude-opus-4-5-20251101)
• Terminal: iTerm2 on macOS
• OS: Darwin 25.1.0

Settings

{
  "model": "opus",
  "alwaysThinkingEnabled": true
}

No custom hooks configured.

Reproduction

1. Start Claude Code with Opus 4.5 model
2. Give Claude a multi-step task that takes several turns
3. Observe iTerm2 notifications firing during active processing, not just idle periods

Workaround

Disabling terminal bell/notifications in iTerm2 preferences.