fix(TASK-26): Rename fedimintd to "Fedimint Guardian"

Added fedimintd to the metadata map with title "Fedimint Guardian"
and description clarifying it's the federation consensus node.
Shares the fedimint.png icon.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

core/archipelago/src/container/docker_packages.rs

@@ -282,9 +282,9 @@ fn get_app_metadata(app_id: &str) -> AppMetadata {
             repo: "https://github.com/joaovitoriasilva/endurain".to_string(),
             tier: "",
         },
-        "fedimint" => AppMetadata {
-            title: "Fedimint".to_string(),
-            description: "Federated Bitcoin mint with Guardian and Gateway".to_string(),
+        "fedimint" | "fedimintd" => AppMetadata {
+            title: "Fedimint Guardian".to_string(),
+            description: "Federated Bitcoin mint — Guardian node for federation consensus".to_string(),
             icon: "/assets/img/app-icons/fedimint.png".to_string(),
             repo: "https://github.com/fedimint/fedimint".to_string(),
             tier: "",