hst: optionally reject insecure options

This prevents inadvertent use of insecure compatibility features.

Closes #30.

Signed-off-by: Ophestra <cat@gensokyo.uk>

nixos.nix

@@ -265,7 +265,7 @@ in
                     '';
                 in
                 pkgs.writeShellScriptBin app.name ''
-                  exec hakurei${if app.verbose then " -v" else ""} run ${checkedConfig "hakurei-app-${app.name}.json" conf} $@
+                  exec hakurei${if app.verbose then " -v" else ""}${if app.insecureWayland then " --insecure" else ""} run ${checkedConfig "hakurei-app-${app.name}.json" conf} $@
                 ''
               )
             ]