Document worst-case startup latency from daemon state polling

[JordanCoin]

Context

hookSessionStart has a worst-case startup path:

1. startDaemon sleeps 200ms waiting for daemon init
2. If ReadState returns nil but daemon is running, waitForDaemonState polls at 100ms intervals for up to 2s

Total worst-case: ~2.2s added to session-start hook before any output appears.

Suggested action

This is informational, not a bug. Options:

• Accept as-is (2.2s is fine for a one-time session-start)
• Reduce waitForDaemonState timeout if users report slow startup
• Consider logging a message during the wait so it doesn't feel like a hang (e.g. "Waiting for daemon...")

Flagged during review of #22 for visibility.