refactor: rename data/openfootball → data/wikipedia, drop data/kaggle

Move world_cup.csv to app/data/ directly (the only remaining Kaggle file
used by seed.ts for tournament metadata). Delete the rest of the Kaggle CSVs.
Update path constants in scrape-wikipedia.ts and seed.ts accordingly.

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

app/data/wikipedia/1982/worldcup.stadiums.json

@@ -0,0 +1,80 @@
+{
+  "stadiums": [
+    {
+      "name": "Camp Nou",
+      "city": "Barcelona"
+    },
+    {
+      "name": "Ramón Sánchez Pizjuán Stadium",
+      "city": "Seville"
+    },
+    {
+      "name": "Estadio José Rico Pérez",
+      "city": "Alicante"
+    },
+    {
+      "name": "Santiago Bernabéu",
+      "city": "Madrid"
+    },
+    {
+      "name": "Balaídos",
+      "city": "Vigo"
+    },
+    {
+      "name": "Estadio de Riazor",
+      "city": "A Coruña"
+    },
+    {
+      "name": "El Molinón",
+      "city": "Gijón"
+    },
+    {
+      "name": "Estadio Carlos Tartiere",
+      "city": "Oviedo"
+    },
+    {
+      "name": "Nuevo Estadio",
+      "city": "Elche"
+    },
+    {
+      "name": "San Mamés",
+      "city": "Bilbao"
+    },
+    {
+      "name": "Estadio José Zorrilla",
+      "city": "Valladolid"
+    },
+    {
+      "name": "Estadio Luis Casanova",
+      "city": "Valencia"
+    },
+    {
+      "name": "La Romareda",
+      "city": "Zaragoza"
+    },
+    {
+      "name": "Ramón Sánchez Pizjuán",
+      "city": "Seville"
+    },
+    {
+      "name": "La Rosaleda Stadium",
+      "city": "Málaga"
+    },
+    {
+      "name": "Estadio Benito Villamarín",
+      "city": "Seville"
+    },
+    {
+      "name": "Sarrià Stadium",
+      "city": "Barcelona"
+    },
+    {
+      "name": "Estadio Sarriá",
+      "city": "Barcelona"
+    },
+    {
+      "name": "Vicente Calderón",
+      "city": "Madrid"
+    }
+  ]
+}