Split DANGEROUS_PATHS into two categories:
1. DANGEROUS_SYSTEM_PATHS: Block path AND all subdirectories
(e.g., /etc, /etc/passwd, /var/log/auth.log)
2. DANGEROUS_HOME_CONTAINERS: Block ONLY exact match
(e.g., /home is blocked but /home/user/project passes through)
This fixes the issue where /home/user/project was incorrectly blocked
by is_dangerous_path(). Subdirectory access control for home directories
is properly delegated to is_home_directory_root() in resolve_and_validate_path().
Addresses review feedback from @chatgpt-codex-connector about blocking
all home directory subpaths.
e5548acb98