refactor: replace hardcoded hex colors with theme tokens, move data/ to root

- Add --color-green-mid token (#4a7a55) to @theme for dimmer stat values
- Replace all text-[#hex]/bg-[#hex] arbitrary values with named tokens:
  text-green, text-green-light, text-green-sec, text-green-muted,
  text-green-dark, text-green-mid, text-text, bg-card, bg-bg, border-border
- Replace rgba(34,197,94,X) inline styles with bg-green/X opacity modifiers
- Convert single-prop style={{ borderColor/background }} to className
- Fix SVG stroke="#dff5e8" → stroke="currentColor"
- Use CSS variables in globals.css base styles (background-color, color)
- Move app/data/wikipedia/ → data/ (project root, not inside Next.js app dir)
- Update Dockerfile, seed.ts, scrape-wikipedia.ts paths accordingly
- Remove unused app/data/world_cup.csv

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

data/2002/worldcup.groups.json

@@ -0,0 +1,76 @@
+{
+  "groups": [
+    {
+      "name": "Group A",
+      "teams": [
+        "France",
+        "Senegal",
+        "Uruguay",
+        "Denmark"
+      ]
+    },
+    {
+      "name": "Group B",
+      "teams": [
+        "Paraguay",
+        "South Africa",
+        "Spain",
+        "Slovenia"
+      ]
+    },
+    {
+      "name": "Group C",
+      "teams": [
+        "Brazil",
+        "Turkey",
+        "China",
+        "Costa Rica"
+      ]
+    },
+    {
+      "name": "Group D",
+      "teams": [
+        "South Korea",
+        "Poland",
+        "United States",
+        "Portugal"
+      ]
+    },
+    {
+      "name": "Group E",
+      "teams": [
+        "Republic of Ireland",
+        "Cameroon",
+        "Germany",
+        "Saudi Arabia"
+      ]
+    },
+    {
+      "name": "Group F",
+      "teams": [
+        "Argentina",
+        "Nigeria",
+        "England",
+        "Sweden"
+      ]
+    },
+    {
+      "name": "Group G",
+      "teams": [
+        "Croatia",
+        "Mexico",
+        "Italy",
+        "Ecuador"
+      ]
+    },
+    {
+      "name": "Group H",
+      "teams": [
+        "Japan",
+        "Belgium",
+        "Russia",
+        "Tunisia"
+      ]
+    }
+  ]
+}

data/2002/worldcup.meta.json

@@ -0,0 +1,8 @@
+{
+  "host": "Japan / South Korea",
+  "teams_count": 32,
+  "winner": "Brazil",
+  "runner_up": "Germany",
+  "third_place": "Turkey",
+  "fourth_place": "South Korea"
+}

data/2002/worldcup.stadiums.json

@@ -0,0 +1,116 @@
+{
+  "stadiums": [
+    {
+      "name": "Jeju World Cup Stadium",
+      "city": "Seogwipo"
+    },
+    {
+      "name": "Big Swan Stadium",
+      "city": "Niigata"
+    },
+    {
+      "name": "Big Eye Stadium",
+      "city": "Ōita"
+    },
+    {
+      "name": "Suwon World Cup Stadium",
+      "city": "Suwon"
+    },
+    {
+      "name": "Jeonju World Cup Stadium",
+      "city": "Jeonju"
+    },
+    {
+      "name": "Kobe Wing Stadium",
+      "city": "Kobe"
+    },
+    {
+      "name": "Miyagi Stadium",
+      "city": "Rifu"
+    },
+    {
+      "name": "Daejeon World Cup Stadium",
+      "city": "Daejeon"
+    },
+    {
+      "name": "Stadium Ecopa",
+      "city": "Fukuroi"
+    },
+    {
+      "name": "Munsu Cup Stadium",
+      "city": "Ulsan"
+    },
+    {
+      "name": "Gwangju World Cup Stadium",
+      "city": "Gwangju"
+    },
+    {
+      "name": "Nagai Stadium",
+      "city": "Osaka"
+    },
+    {
+      "name": "Seoul World Cup Stadium",
+      "city": "Seoul"
+    },
+    {
+      "name": "Saitama Stadium",
+      "city": "Saitama"
+    },
+    {
+      "name": "Daegu World Cup Stadium",
+      "city": "Daegu"
+    },
+    {
+      "name": "International Stadium",
+      "city": "Yokohama"
+    },
+    {
+      "name": "Busan Asiad Main Stadium",
+      "city": "Busan"
+    },
+    {
+      "name": "Incheon World Cup Stadium",
+      "city": "Incheon"
+    },
+    {
+      "name": "Munsu Football Stadium",
+      "city": "Ulsan"
+    },
+    {
+      "name": "Niigata Stadium",
+      "city": "Niigata"
+    },
+    {
+      "name": "Sapporo Dome",
+      "city": "Sapporo"
+    },
+    {
+      "name": "Kashima Soccer Stadium",
+      "city": "Ibaraki"
+    },
+    {
+      "name": "Ecopa Stadium",
+      "city": "Shizuoka"
+    },
+    {
+      "name": "International Stadium Yokohama",
+      "city": "Yokohama"
+    },
+    {
+      "name": "Wing Stadium",
+      "city": "Kobe"
+    },
+    {
+      "name": "Niigata Big Swan Stadium",
+      "city": "Niigata"
+    },
+    {
+      "name": "Ōita Big Eye Stadium",
+      "city": "Ōita"
+    },
+    {
+      "name": "Shizuoka Ecopa Stadium",
+      "city": "Fukuroi, Shizuoka"
+    }
+  ]
+}