sb-api: label helpers wiring + gym/stat_value + policy constants (WI-2, issue #2)

crates/sb-core/src/spells.rs

@@ -110,4 +110,9 @@ mod tests {
             );
         }
     }
+
+    #[test]
+    fn spells_json_parses() {
+        assert!(!load_spells().is_empty());
+    }
 }