feat(admin,api): restrict community creation on self-hosted (#3055)

fluxer_admin/src/admin_hints.rs

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use crate::templates::components::tooltip::{Hint, HintLink};
+
+pub fn limit_key_hint(key: &str) -> Option<Hint<'static>> {
+    match key {
+        "feature_guild_create" => Some(Hint {
+            name: Some("Community Creation Access"),
+            body: "Admins with the wildcard ACL can always create communities.",
+            link: Some(HintLink::new(
+                "/instance-config#community-creation",
+                "Community creation policy",
+            )),
+        }),
+        _ => None,
+    }
+}