Function detect_pam_fingerprint 

pub fn detect_pam_fingerprint(tool: PrivilegeTool) -> bool

What: Detect whether the active privilege tool’s PAM configuration includes pam_fprintd.

Inputs:

• tool: Resolved privilege tool (sudo or doas).

Output:

• true if /etc/pam.d/{tool} exists and contains a reference to pam_fprintd.

Details:

• Reads /etc/pam.d/sudo or /etc/pam.d/doas and checks for pam_fprintd.so.
• Also checks /etc/pam.d/system-auth and /etc/pam.d/system-local-login as common include targets where pam_fprintd may be configured instead of the tool-specific file.
• Informational only — never blocks execution.
• Returns false on any I/O error (missing file, permission denied).