Make nix profile install an alias of nix profile add

doc/manual/meson.build

@@ -248,7 +248,6 @@ nix3_manpages = [
   'nix3-print-dev-env',
   'nix3-profile-diff-closures',
   'nix3-profile-history',
-  'nix3-profile-install',
   'nix3-profile-list',
   'nix3-profile',
   'nix3-profile-remove',

src/nix/profile.cc

@@ -984,10 +984,12 @@ struct CmdProfile : NixMultiCommand
               {"history", []() { return make_ref<CmdProfileHistory>(); }},
               {"rollback", []() { return make_ref<CmdProfileRollback>(); }},
               {"wipe-history", []() { return make_ref<CmdProfileWipeHistory>(); }},
-              // 2025-04-05 Deprecated in favor of "add"
-              {"install", []() { return make_ref<CmdProfileAdd>(); }},
           })
-    { }
+    {
+        aliases = {
+            {"install", { AliasStatus::Deprecated, {"add"}}},
+        };
+    }
 
     std::string description() override
     {