Inline `node -e "..."` in hooks.json contained `!` characters (e.g.
`!org.isDirectory()`) that bash history expansion in certain shell
environments would misinterpret, producing syntax errors and the
"SessionStart:startup hook error" banner in the Claude Code CLI header.
Extract the bootstrap logic to `scripts/hooks/session-start-bootstrap.js`
so the shell never sees the JS source. Behaviour is identical: the script
reads stdin, resolves the ECC plugin root via CLAUDE_PLUGIN_ROOT or a set
of well-known fallback paths, then delegates to run-with-flags.js.
Update the test that asserted the old inline pattern to verify the new
file-based approach instead.
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
