feat(frontend): authentification frontend

ajout de la page login, changement de mot de passe forcé, rafraîchissement de session en mémoire, intercepteur, déconnexion, bouton logout sur le dashboard

apps/frontend/src/app/features/auth/login/login.scss

@@ -0,0 +1,81 @@
+:host {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  min-height: 100vh;
+  background: #f3f4f6;
+  font-family: 'Segoe UI', system-ui, sans-serif;
+}
+
+.auth-card {
+  background: #ffffff;
+  border: 1px solid #e5e7eb;
+  border-radius: 12px;
+  padding: 2.5rem;
+  width: 100%;
+  max-width: 360px;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
+  display: flex;
+  flex-direction: column;
+
+  h1 {
+    margin: 0;
+    font-size: 1.5rem;
+    font-weight: 700;
+    color: #1f2937;
+  }
+
+  .auth-subtitle {
+    margin: 0.25rem 0 1.5rem;
+    color: #6b7280;
+    font-size: 0.9rem;
+  }
+
+  label {
+    font-size: 0.85rem;
+    font-weight: 600;
+    color: #374151;
+    margin-bottom: 0.35rem;
+    margin-top: 1rem;
+  }
+
+  input {
+    padding: 0.6rem 0.75rem;
+    border: 1px solid #d1d5db;
+    border-radius: 8px;
+    font-size: 0.95rem;
+
+    &:focus {
+      outline: none;
+      border-color: #3b82f6;
+      box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
+    }
+  }
+
+  button {
+    margin-top: 1.5rem;
+    padding: 0.7rem;
+    background: #3b82f6;
+    color: #fff;
+    border: none;
+    border-radius: 8px;
+    font-size: 0.95rem;
+    font-weight: 600;
+    cursor: pointer;
+
+    &:disabled {
+      background: #9ca3af;
+      cursor: not-allowed;
+    }
+
+    &:not(:disabled):hover {
+      background: #2563eb;
+    }
+  }
+}
+
+.auth-error {
+  margin: 0.75rem 0 0;
+  color: #dc2626;
+  font-size: 0.85rem;
+}