chore: remove features.old archive and format all files

- Delete home/features.old/ (archived old flat feature modules)
- All content migrated to new profile-based structure
- Run alejandra formatter over 13 changed files
- nix flake check passes cleanly

home/lib/default.nix

@@ -8,9 +8,7 @@
 #       (homeLib.mkHomeConfig { profiles = ["coding" "gaming"]; context = "desktop"; })
 #     ];
 #   }
-{ lib }:
-
-let
+{lib}: let
   # Infrastructure layer — nixpkgs overlays, nix-colors, m3ta-nixpkgs modules.
   # Always loaded on every host.
   commonModule = ../common;
@@ -31,7 +29,6 @@ let
     gaming = ../profiles/gaming;
     media = ../profiles/media;
   };
-
 in {
   # Generate a home-manager module with imports based on profiles and context.
   #
@@ -46,36 +43,41 @@ in {
   mkHomeConfig = {
     profiles ? [],
     context ? null,
-  }:
-  let
+  }: let
     contextImport =
-      if context == "desktop" then [ contextModuleMap.desktop ]
-      else if context == "server" then [ contextModuleMap.server ]
+      if context == "desktop"
+      then [contextModuleMap.desktop]
+      else if context == "server"
+      then [contextModuleMap.server]
       else [];
 
     # Partition profiles into known and unknown for assertion + safe import.
-    unknownProfiles = builtins.filter
+    unknownProfiles =
+      builtins.filter
       (profileName: ! builtins.hasAttr profileName profileModuleMap)
       profiles;
 
     # Only import known profiles; the assertion below catches unknowns.
-    activeProfiles = builtins.filter
+    activeProfiles =
+      builtins.filter
       (profileName: builtins.hasAttr profileName profileModuleMap)
       profiles;
 
     profileImports = map (profileName: profileModuleMap.${profileName}) activeProfiles;
 
-    contextStr = if context == null then "null" else context;
-
+    contextStr =
+      if context == null
+      then "null"
+      else context;
   in {
     imports =
-      [ commonModule baseModule ]
+      [commonModule baseModule]
       ++ contextImport
       ++ profileImports;
 
     assertions = [
       {
-        assertion = builtins.elem context [ "desktop" "server" null ];
+        assertion = builtins.elem context ["desktop" "server" null];
         message =
           "m3ta home: context must be 'desktop', 'server', or null"
           + " (got: '${contextStr}')";