feat(quotesdb): GET /api/status public endpoint

Adds the GET /api/status handler that returns {"submissions_locked": bool}.
Registers the route in the router before the quotes routes.
Adds three unit tests covering unlocked state, locked state, and default false.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

quotesdb/src/bin/api/handlers/mod.rs

@@ -159,6 +159,25 @@ async fn openapi_handler() -> Response {
         .into_response()
 }
 
+/// `GET /api/status` — return whether quote submissions are currently locked.
+///
+/// This endpoint requires no authentication and is intended to be called by
+/// the UI on mount for both the `/submit` and `/admin` pages. Returns a JSON
+/// object with a single boolean field:
+///
+/// ```json
+/// { "submissions_locked": false }
+/// ```
+///
+/// Returns `500 Internal Server Error` if the database query fails.
+#[cfg_attr(target_arch = "wasm32", worker::send)]
+pub async fn get_status(State(repo): State<Repo>) -> Response {
+    match repo.get_submissions_locked().await {
+        Ok(locked) => Json(serde_json::json!({ "submissions_locked": locked })).into_response(),
+        Err(_) => StatusCode::INTERNAL_SERVER_ERROR.into_response(),
+    }
+}
+
 /// `GET /api/quotes` — list quotes with optional filtering and pagination.
 ///
 /// Accepts `?page=N&author=X&tag=Y&date_after_year=Y&date_before_year=Y` (and
@@ -394,6 +413,8 @@ pub fn router(repo: Arc<dyn QuoteRepository + Send + Sync>) -> Router {
     Router::new()
         // Meta
         .route("/api/", get(openapi_handler))
+        // Public status — exposes whether submissions are currently locked.
+        .route("/api/status", get(get_status))
         // IMPORTANT: /random must be registered before /{id} so the static
         // segment wins over the dynamic capture.
         .route("/api/quotes/random", get(random_handler))
@@ -878,6 +899,56 @@ mod tests {
             "expected Forbidden, got {result:?}",
         );
     }
+
+    // ── GET /api/status handler tests ─────────────────────────────────────────
+
+    /// `GET /api/status` returns `200` with `{"submissions_locked": false}` when
+    /// the repo's submissions lock is unset (the default `false` state).
+    #[tokio::test]
+    async fn test_get_status_unlocked() {
+        let app = router(MockRepo::empty());
+        let req = Request::builder()
+            .method(Method::GET)
+            .uri("/api/status")
+            .body(Body::empty())
+            .unwrap();
+        let (status, body) = send(app, req).await;
+        assert_eq!(status, StatusCode::OK);
+        let v: serde_json::Value = serde_json::from_str(&body).unwrap();
+        assert_eq!(v["submissions_locked"], false);
+    }
+
+    /// `GET /api/status` returns `200` with `{"submissions_locked": true}` after
+    /// the lock has been enabled via `set_submissions_locked(true)`.
+    #[tokio::test]
+    async fn test_get_status_locked() {
+        let repo = MockRepo::empty();
+        repo.set_submissions_locked(true)
+            .await
+            .expect("set_submissions_locked should not fail");
+        let app = router(repo);
+        let req = Request::builder()
+            .method(Method::GET)
+            .uri("/api/status")
+            .body(Body::empty())
+            .unwrap();
+        let (status, body) = send(app, req).await;
+        assert_eq!(status, StatusCode::OK);
+        let v: serde_json::Value = serde_json::from_str(&body).unwrap();
+        assert_eq!(v["submissions_locked"], true);
+    }
+
+    /// `get_submissions_locked` returns `false` for a freshly created repo
+    /// (graceful default — no DB row or explicit seed needed).
+    #[tokio::test]
+    async fn test_get_submissions_locked_default_is_false() {
+        let repo = MockRepo::empty();
+        let locked = repo
+            .get_submissions_locked()
+            .await
+            .expect("get_submissions_locked should not fail");
+        assert!(!locked, "submissions should default to unlocked");
+    }
 }
 
 // ── Integration tests (real NativeRepository + real SQLite) ─────────────────