Add Indianapolis oval (1950-1960) and Madring (2026) circuits

Indianapolis oval layout uses real OSM centerline data for the
2.5-mile oval used in the F1 championship from 1950-1960.
Madring is the new Madrid circuit for the 2026 Spanish Grand Prix,
track path extracted from Wikimedia SVG.

circuits/circuits.json

@@ -1253,6 +1253,19 @@
                 "imageUrl": null
               }
             }
+          },
+          "madring": {
+            "name": "Madring",
+            "urls": {
+              "wikipedia": "https://en.wikipedia.org/wiki/Madring",
+              "fandom": "https://f1.fandom.com/wiki/Madring"
+            },
+            "layouts": {
+              "2026-": {
+                "description": "5.416 km semi-urban circuit at IFEMA Madrid featuring 22 corners including the banked 'La Monumental' curve.",
+                "imageUrl": "https://static.wikia.nocookie.net/f1wikia/images/f/f1/Madring.svg"
+              }
+            }
           }
         },
         "name": "Madrid"
@@ -1618,6 +1631,10 @@
               "2000-2007": {
                 "description": "Combined oval and infield layout running clockwise, featuring a series of right and left-hand turns including 'Mickey' and 'Mouse' corners, with issues related to banked corners affecting tire performance.",
                 "imageUrl": "https://static.wikia.nocookie.net/f1wikia/images/7/74/IMS_road.svg"
+              },
+              "1950-1960": {
+                "description": "The full 2.5-mile oval used for the Indianapolis 500, which was part of the Formula One World Championship from 1950 to 1960.",
+                "imageUrl": "https://static.wikia.nocookie.net/f1wikia/images/6/61/IMS_oval.svg"
               }
             }
           }