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/2022/worldcup.stadiums.json

@@ -0,0 +1,36 @@
+{
+  "stadiums": [
+    {
+      "name": "Khalifa International Stadium",
+      "city": "Al Rayyan"
+    },
+    {
+      "name": "Ahmad bin Ali Stadium",
+      "city": "Al Rayyan"
+    },
+    {
+      "name": "Al Thumama Stadium",
+      "city": "Doha"
+    },
+    {
+      "name": "Al Bayt Stadium",
+      "city": "Al Khor"
+    },
+    {
+      "name": "Al Janoub Stadium",
+      "city": "Al Wakrah"
+    },
+    {
+      "name": "Stadium 974",
+      "city": "Doha"
+    },
+    {
+      "name": "Education City Stadium",
+      "city": "Al Rayyan"
+    },
+    {
+      "name": "Lusail Stadium",
+      "city": "Lusail"
+    }
+  ]
+}