This PR prevents popup of "Restore pages?" prompt when Clawdbot launches chrome browsers. The prompt wasn't blocking any functionality but was visually annoying.

I've tested this.

Codex prompt:

Fix Chrome "Restore pages?" prompt for Clawdbot browser profiles.

Context:

• Clawdbot manages multiple Chrome profiles at ~/.clawdbot/browser/{profile}/user-data/
• Chrome shows "Restore pages?" dialog on startup after unclean shutdown
• This is annoying

Goals:

1. Prevent the restore prompt from appearing
2. Apply fix to all Clawdbot browser profiles

Approaches to consider:

• Set Chrome preferences in Default/Preferences JSON (exit_type, exited_cleanly)
• Add Chrome launch flags (--disable-session-crashed-bubble, --hide-crash-restore-bubble)
• Modify profile Preferences file on browser stop/start

Deliverable:

• Identify the best approach
• Implement it (either via launch flags in Clawdbot config or a script to patch Preferences files)
• Test that the prompt no longer appears