Function check_db_lock 

pub fn check_db_lock(ctx: &GuardrailContext) -> Option<GuardrailIssue>

What: Check whether the pacman database is locked.

Inputs:

• ctx: Guardrail context providing the lock path and proc dir.

Output:

• Some(GuardrailIssue::DbLocked) when the lock file exists; None otherwise.

Details:

• Also reports whether a package manager process is running so callers can distinguish “wait for it to finish” from “remove the stale lock”.