chore: finish frontend ESLint migration #18

Enable every plugin recommended preset and replace Biome with ESLint formatting.

Preserve API contracts and JSX whitespace; verify source, tests, builds and tooling.

src/test/handlers.ts

@@ -1,9 +1,10 @@
-import { HttpResponse, http } from "msw";
+import { http, HttpResponse } from "msw";
+
 import { resource } from "@/test/resource";
 
 const authentication = {
 	accessToken: "test-token",
-	user: { id: "user-1", email: "user@example.com" },
+	user: { email: "user@example.com", id: "user-1" },
 };
 
 const handlers = [
@@ -18,7 +19,9 @@ const handlers = [
 	),
 	http.get("*/api/v1/auth/me", () => HttpResponse.json(authentication.user)),
 	http.get("*/api/v1/tbank-connection", () =>
-		HttpResponse.json({ connected: false, connectedAt: null }),
+		HttpResponse.json((/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+			{ connected: false, connectedAt: null }
+			/* eslint-enable unicorn/no-null */)),
 	),
 	http.put("*/api/v1/tbank-connection", () =>
 		HttpResponse.json({ connected: true, connectedAt: "2026-08-14T00:00:00Z" }),
@@ -33,24 +36,26 @@ const handlers = [
 	http.get("*/api/v1/brokerage-accounts/:accountId/portfolio", () =>
 		HttpResponse.json(
 			resource({
-				lastSuccessfulAt: "2026-08-14T00:00:00Z",
+				cashBalances: [],
 				isStale: false,
-				totalsByCurrency: [],
+				lastSuccessfulAt: "2026-08-14T00:00:00Z",
 				positions: [],
 				structure: { currencies: [], unvaluedCategories: [] },
-				cashBalances: [],
+				totalsByCurrency: [],
 			}),
 		),
 	),
 	http.get("*/api/v1/brokerage-accounts/:accountId/operations", () =>
 		HttpResponse.json(
-			resource({
-				accountId: "account-1",
-				items: [],
-				nextCursor: null,
-				hasNext: false,
-				observedAt: "2026-08-14T00:00:00Z",
-			}),
+			resource((/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+				{
+					accountId: "account-1",
+					hasNext: false,
+					items: [],
+					nextCursor: null,
+					observedAt: "2026-08-14T00:00:00Z",
+				}
+				/* eslint-enable unicorn/no-null */)),
 		),
 	),
 	http.get("*/api/v1/brokerage-accounts/:accountId/events", () =>
@@ -66,9 +71,9 @@ const handlers = [
 		HttpResponse.json(
 			resource({
 				accountId: "account-1",
+				calculatedAt: "2026-08-14T00:00:00Z",
 				period: { from: "2026-01-01", to: "2026-08-14" },
 				totalsByCurrency: [],
-				calculatedAt: "2026-08-14T00:00:00Z",
 			}),
 		),
 	),