buildRestartCommand() now propagates Claude-related env vars when
respawning sessions via tmux. Fresh shells don't inherit parent env,
so CLAUDE_CODE_USE_BEDROCK, ANTHROPIC_API_KEY, AWS_*, etc. were lost.
This caused any tmux respawn to result in a non-functional claude.
Adds claudeEnvVars list and includes them in the export command when
building the restart command.