fix(greeter): reimplement regression to hide debug logs during login

- Provide more status feedback
- Allow 2 fprint tries within 10 seconds for DMS-managed PAM
- Updated dms greeter docs

Note: distro-managed PAM takes precedence and may use different limits.
DMS auth changes remain conditional on greetd being installed.

Fixes #2853
Port 1.5

quickshell/Modules/Greetd/README.md

@@ -51,12 +51,44 @@ dms greeter enable
 dms greeter sync
 ```
 
+Fingerprint authentication is optional. Install your distribution's
+fingerprint service/client and PAM integration before enabling it. Package
+names vary by distribution; on Fedora the native stack is:
+
+```bash
+sudo dnf install fprintd fprintd-pam
+fprintd-enroll
+```
+
+The distro `fprintd` package normally pulls in `libfprint` automatically. After
+enrollment, enable fingerprint login in **Settings → Greeter**. The toggle
+applies the shared PAM configuration automatically, so no additional sync is
+needed after initial greeter setup. Use `dms auth sync` only to repair or apply
+authentication manually without syncing the rest of the greeter.
+
+greetd tries fingerprint and password sequentially. DMS-managed PAM allows two
+scans for up to ten seconds before password fallback. Existing distro PAM
+policy takes precedence, so fallback timing can differ.
+
+Verify enrollment with `fprintd-list "$USER"`; pass a token such as
+`fprintd-enroll -f right-thumb` to enroll a specific finger. Security keys
+similarly require `pam_u2f` setup and key registration before enabling the
+login toggle.
+
+If `fprintd-enroll` reports **No devices available**, check the [libfprint
+supported devices list](https://fprint.freedesktop.org/supported-devices.html).
+Some Validity/Synaptics readers are not supported by the native stack,
+regardless of distribution; the
+[open-fprintd](https://github.com/uunicorn/open-fprintd) service with the
+[python-validity](https://github.com/uunicorn/python-validity) driver may work
+instead. Follow the driver's installation and firmware instructions, and do
+not run the stock `fprintd` daemon alongside its replacement.
+
 #### Syncing themes (Optional)
 
 To sync your wallpaper and theme with the greeter login screen, follow the manual setup below:
 
-<details>
-<summary>Manual theme syncing</summary>
+##### Manual theme syncing
 
 ```bash
 # Add yourself to greeter group