Your team uses a shared monorepo where Claude Code is typically launched from the repository root. A senior engineer has set up a .claude/hooks/ directory in a shared library subdirectory (/repo/libs/shared/.claude/hooks/) to enforce code style checks before edits. Developers on the platform team start using --add-dir /repo/libs/shared to give Claude access to the shared library's files. Two weeks later, they report that Claude is editing shared library files without triggering the hooks. Logs confirm Claude reads and writes files in /repo/libs/shared but the hooks never fire. What is the root cause?