chore(deps): update typescript to v6

TypeScript 6 deprecates baseUrl and checks side-effect imports. Drop baseUrl, which paths does not need, and load the vite/client types so the CSS import resolves. Remove trailing commas from tsconfig.json so the JSON hook accepts it.

frontend/tsconfig.json

@@ -11,15 +11,15 @@
         "isolatedModules": true,
         "noEmit": true,
         "jsx": "preserve",
+        "types": ["vite/client"],
         "strict": true,
         "noUnusedLocals": true,
         "noUnusedParameters": true,
         "noFallthroughCasesInSwitch": true,
-        "baseUrl": ".",
         "paths": {
-            "@/*": ["./src/*"],
-        },
+            "@/*": ["./src/*"]
+        }
     },
     "include": ["src/**/*.ts", "src/**/*.d.ts", "src/**/*.tsx", "src/**/*.vue"],
-    "references": [{ "path": "./tsconfig.node.json" }],
+    "references": [{ "path": "./tsconfig.node.json" }]
 }