fix: migration first-boot, fingerprint PAM, menus, mic LED

Post-migration annoyances from TuringMachine:

- Force fprintAuth from fingerprint.pam (NixOS defaults it on with fprintd)
- First-boot toast waits for swaync, retries, only marks after success
- Night light status/toggle handles masked units + hyprsunset/wlsunset
- VPN menu: define rofi_menu in nomarchy-vpn (was a silent no-op)
- Left arrow = ↩ Back in list menus; GTK menu contrast via Stylix
- Mic-mute LED udev + sync after wpctl; EasyEffects starts after tray
- Migration guide: HM before GUI login, fingerprint/browser/VPN notes

Verified: flake check --no-build; checks.first-boot; checks.hardware-toggles
(pam=false node). V3 session items pending after user rebuild.

modules/home/stylix.nix

@@ -45,7 +45,56 @@ in
       base16Scheme = base16;
 
       targets = {
-        gtk.enable = true;
+        gtk = {
+          enable = true;
+          # nm-applet / classic GTK menus: Stylix base16 selection can
+          # collapse into surface/muted on dark themes (Boreal: selected
+          # row and submenu arrows were effectively invisible). High-
+          # contrast selected rows + explicit arrow colour. Appended to
+          # Stylix's generated gtk.css (not gtk.gtk3.extraCss — that is a
+          # no-op under Stylix).
+          extraCss = ''
+            menu menuitem, .menu menuitem, .context-menu menuitem {
+              color: #${base16.base05};
+            }
+            menu menuitem:hover, menu menuitem:selected,
+            .menu menuitem:hover, .menu menuitem:selected,
+            .context-menu menuitem:hover, .context-menu menuitem:selected,
+            menubar > menuitem:hover {
+              background-color: #${base16.base0D};
+              color: #${base16.base00};
+            }
+            menu menuitem:disabled, .menu menuitem:disabled {
+              color: #${base16.base03};
+            }
+            /* Submenu disclosure arrows — without this they pick muted. */
+            menu menuitem arrow, .menu menuitem arrow,
+            menu menuitem:hover arrow, menu menuitem:selected arrow {
+              min-width: 16px;
+              min-height: 16px;
+              margin-left: 8px;
+              color: inherit;
+              -gtk-icon-source: -gtk-icontheme("pan-end-symbolic");
+            }
+            menu menuitem:hover arrow, menu menuitem:selected arrow {
+              color: #${base16.base00};
+            }
+            check, radio {
+              min-width: 14px;
+              min-height: 14px;
+              color: inherit;
+            }
+            /* GTK4 / popover menus (some portals). */
+            popover.menu contents modelbutton {
+              color: #${base16.base05};
+            }
+            popover.menu contents modelbutton:hover,
+            popover.menu contents modelbutton:selected {
+              background-color: #${base16.base0D};
+              color: #${base16.base00};
+            }
+          '';
+        };
         qt.enable = true;
         # No-op unless programs.zathura is on (viewers.nix enables it).
         zathura.enable = true;