refactor(channels): centralize runtime group policy handling

extensions/discord/src/channel.ts

@@ -22,7 +22,7 @@ import {
   resolveDefaultDiscordAccountId,
   resolveDiscordGroupRequireMention,
   resolveDiscordGroupToolPolicy,
-  resolveRuntimeGroupPolicy,
+  resolveOpenProviderRuntimeGroupPolicy,
   setAccountEnabledInConfigSection,
   type ChannelMessageActionAdapter,
   type ChannelPlugin,
@@ -132,12 +132,10 @@ export const discordPlugin: ChannelPlugin<ResolvedDiscordAccount> = {
     collectWarnings: ({ account, cfg }) => {
       const warnings: string[] = [];
       const defaultGroupPolicy = cfg.channels?.defaults?.groupPolicy;
-      const { groupPolicy } = resolveRuntimeGroupPolicy({
+      const { groupPolicy } = resolveOpenProviderRuntimeGroupPolicy({
         providerConfigPresent: cfg.channels?.discord !== undefined,
         groupPolicy: account.config.groupPolicy,
         defaultGroupPolicy,
-        configuredFallbackPolicy: "open",
-        missingProviderFallbackPolicy: "allowlist",
       });
       const guildEntries = account.config.guilds ?? {};
       const guildsConfigured = Object.keys(guildEntries).length > 0;