feat: DEFAULT_LANGUAGE/DEFAULT_TIMEZONE config + public GET /api/config

crates/api/src/lib.rs

@@ -5,6 +5,7 @@ mod admin_authorities;
 mod admin_objects;
 mod admin_search;
 mod admin_vocab;
+mod config;
 mod health;
 mod openapi;
 mod pagination;
@@ -30,6 +31,10 @@ pub struct AppState {
     /// Search client for on-write index sync. `None` disables indexing (search is a
     /// best-effort feature; absent when Meilisearch is not configured).
     pub search: Option<search::SearchClient>,
+    /// Instance default UI/content language (from config).
+    pub default_language: String,
+    /// Instance default display timezone, IANA name (from config). Storage stays UTC.
+    pub default_timezone: String,
 }
 
 /// Best-effort: keep the search index in step with a catalogue write that has already
@@ -58,6 +63,7 @@ pub fn build_app(state: AppState) -> Router {
         .with_expiry(Expiry::OnInactivity(Duration::hours(8)));
 
     Router::new()
+        .merge(config::routes())
         .merge(health::routes())
         .merge(openapi::routes())
         .merge(public::routes())