build: configure absolute imports using @ alias

Configures TypeScript path aliases for cleaner and more maintainable imports.

tsconfig.json

@@ -24,6 +24,12 @@
     // Some stricter flags (disabled by default)
     "noUnusedLocals": false,
     "noUnusedParameters": false,
-    "noPropertyAccessFromIndexSignature": false
-  }
+    "noPropertyAccessFromIndexSignature": false,
+
+    "paths": {
+      "@/*": ["./src/*"]
+    }
+  },
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+  "exclude": ["node_modules"]
 }