Enable app-wide StrictMode and restore React effect checks

tests/react-lint.test.mjs

@@ -0,0 +1,12 @@
+// Rôle : vérifie que les contrôles React critiques restent actifs dans la configuration ESLint effective.
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { ESLint } from "eslint";
+
+test("React effect and purity checks are enabled for application sources", async () => {
+  const eslint = new ESLint();
+  const config = await eslint.calculateConfigForFile("website/src/main.jsx");
+  for (const rule of ["react-hooks/set-state-in-effect", "react-hooks/purity", "react-hooks/rules-of-hooks", "react-hooks/exhaustive-deps"]) {
+    assert.ok(config.rules[rule][0] > 0, `${rule} must remain enabled`);
+  }
+});