enzo: use native firefox preferences policy, not HM profiles

The previous commit used programs.firefox.profiles, which is a Home Manager
option and does not exist in the native NixOS module — the config failed to
evaluate. Switch to programs.firefox.preferences, which the module delivers as
a Firefox enterprise policy applied to every profile.

Covers dark chrome, blank home/new-tab, and hiding the bookmarks toolbar.
Full nav/tab toolbar removal needs userChrome.css, which the native module
cannot ship.

Assisted-by: Claude:claude-opus-4-8

1 files changed, 21 insertions, 28 deletions

diff --git a/machines/enzo/desktop.nix b/machines/enzo/desktop.nix
index 338e75c..b340e7f 100644
--- a/machines/enzo/desktop.nix
+++ b/machines/enzo/desktop.nix
@@ -71,38 +71,31 @@
     "input"
   ];
 
-  # Firefox with declarative customizations: dark chrome, blank home/new-tab,
-  # and toolbars stripped via userChrome.css. Settings here are authoritative on
-  # each rebuild; anything not listed stays adjustable in the UI.
+  # Firefox customizations. The native NixOS module has no profile/userChrome
+  # support (that's Home Manager); instead `preferences` are delivered as a
+  # Firefox enterprise policy (etc/firefox/policies/policies.json), so they
+  # apply to every profile without managing one. preferencesStatus = "default"
+  # means these seed the defaults but stay overridable in the UI.
+  #
+  # This covers dark chrome, blank home/new-tab, and hiding the bookmarks
+  # toolbar. Fully removing the nav/tab toolbars needs userChrome.css, which
+  # this module can't ship — would require Home Manager or an activation hack.
   programs.firefox = {
     enable = true;
+    preferencesStatus = "default";
+    preferences = {
+      # Dark theme (UI chrome + toolbars)
+      "ui.systemUsesDarkTheme" = 1;
+      "browser.theme.content-theme" = 0;
+      "browser.theme.toolbar-theme" = 0;
 
-    profiles.default = {
-      isDefault = true;
+      # Blank home page + blank new tab
+      "browser.startup.homepage" = "about:blank";
+      "browser.startup.page" = 0; # 0 = blank on startup
+      "browser.newtabpage.enabled" = false;
 
-      settings = {
-        # Dark theme (UI chrome + toolbars)
-        "ui.systemUsesDarkTheme" = 1;
-        "browser.theme.content-theme" = 0;
-        "browser.theme.toolbar-theme" = 0;
-
-        # Blank home page + blank new tab
-        "browser.startup.homepage" = "about:blank";
-        "browser.startup.page" = 0; # 0 = blank on startup
-        "browser.newtabpage.enabled" = false;
-
-        # Required for userChrome.css below to load
-        "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
-      };
-
-      # Toolbar removal. Tweak/uncomment to taste.
-      userChrome = ''
-        /* Bookmarks toolbar */
-        #PersonalToolbar { visibility: collapse !important; }
-
-        /* Whole nav + tab strip (uncomment for a truly chromeless window) */
-        /* #navigator-toolbox { visibility: collapse !important; } */
-      '';
+      # Hide the bookmarks toolbar
+      "browser.toolbars.bookmarks.visibility" = "never";
     };
   };