Duplicate subagent nodes rendered when hook server and transcript parser both emit spawn

[kynoptic]

Describe the bug
When a subagent is spawned, two agent nodes appear on the canvas — a ghost node with a generic name like general-purpose-ab75a and the correct node with the subagent's description. The ghost node tracks the same tool calls, creating visual clutter.

Steps to reproduce

1. Run Agent Flow and connect to a Claude Code session
2. In the session, use the Agent tool to spawn a subagent (e.g. with subagent_type: "general-purpose" and a description)
3. Observe the canvas — two nodes appear for the single subagent

Expected behavior
One node per subagent, using the description-based name from the transcript.

Screenshots
N/A — the duplicate node appears as a second hexagon with a truncated generic name alongside the correctly-named node.

Environment

• VS Code version: N/A (standalone dev mode)
• Agent Flow version: 0.6.2
• Node version: v25.6.1
• OS: macOS 15.5 (Darwin 25.3.0)