[Bug] Subagent polling wake-ups consume excessive tokens for no-op status checkssu

Bug Description
Monitor-based subagent polling burns ~150k+ tokens per 30s wake for a no-op status check
▎ A background subagent set up a 30-second polling loop to wait on a long-running git push (pre-push hook running full CI). Each
▎ poll tick woke the subagent's full turn and cost ~146k–160k tokens just to report "still running" — no new work done. Over ~5
▎ minutes of wall-clock time this fired 12+ times, costing an estimated 1.8M+ tokens in pure polling overhead for one background
▎ command. Evidence: task id a8e16d4b621fa3ffb, 12 consecutive notifications with subagent_tokens in the 146k–160k range and
▎ tool_uses: 122 unchanged across several — suggesting the same large context was reprocessed each wake rather than a lightweight
▎ check.

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.247
• Feedback ID: 8263f9a5-d755-43db-b7da-34d6d413c914

Errors

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