core: type workspace and secret timestamps

apps/mcp-server/src/app.rs

@@ -560,7 +560,7 @@ async fn resolve_auth_profile(
     auth_profile: &AuthProfile,
 ) -> Result<ResolvedAuth, RuntimeError> {
     let mut secrets = BTreeMap::new();
-    let used_at = now_rfc3339();
+    let used_at = OffsetDateTime::now_utc();
 
     for secret_id in auth_profile.config.secret_ids() {
         let secret = registry
@@ -1918,10 +1918,6 @@ fn format_rfc3339(timestamp: OffsetDateTime) -> String {
         .unwrap_or_else(|_| "1970-01-01T00:00:00Z".to_owned())
 }
 
-fn now_rfc3339() -> String {
-    format_rfc3339(OffsetDateTime::now_utc())
-}
-
 fn add_millis(timestamp: OffsetDateTime, millis: u64) -> OffsetDateTime {
     let delta = time::Duration::milliseconds(i64::try_from(millis).unwrap_or(i64::MAX));