Module session 

Structs

SessionContext

Session context — holds the session ID, directory, and file lock.

Functions

acquire_session_lock

Acquire an exclusive file lock on the session directory.

cleanup_expired_sessions

Clean up expired sessions.

generate_session_id

Generate a new session_id (format: YYYYMMDD_first8ofUuid)

get_or_create_session_dir

Get or create a session directory under base_dir/sessions/<session_id>.

resolve_session

Resolve and create a session context — session ID, directory, and file lock.

resolve_session_id

Resolve session ID (priority: CLI arg → PHI_SESSION_ID env var → auto-generate).

validate_session_id

Validate session ID format.