feat: add initial application structure with configuration, UI components, and state management

content/fixtures/costs.json

@@ -0,0 +1,38 @@
+{
+  "overheadCosts": [
+    {
+      "id": "overhead-1",
+      "name": "Coworking Space",
+      "amount": 800,
+      "category": "Workspace",
+      "recurring": true,
+      "description": "Shared workspace membership for 3 desks"
+    },
+    {
+      "id": "overhead-2",
+      "name": "Tools & Software",
+      "amount": 420,
+      "category": "Technology",
+      "recurring": true,
+      "description": "Development tools, design software, project management"
+    },
+    {
+      "id": "overhead-3",
+      "name": "Business Insurance",
+      "amount": 180,
+      "category": "Legal & Compliance",
+      "recurring": true,
+      "description": "Professional liability and general business insurance"
+    }
+  ],
+  "productionCosts": [
+    {
+      "id": "production-1",
+      "name": "Development Kits",
+      "amount": 500,
+      "category": "Hardware",
+      "period": "2024-01",
+      "description": "Testing devices and development hardware"
+    }
+  ]
+}