feat(auth): add form login with session

apps/visualizer/src/styles.css

@@ -55,6 +55,72 @@ a:hover {
   box-sizing: border-box;
 }
 
+.loginScreen {
+  height: 100vh;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 24px;
+  box-sizing: border-box;
+}
+
+.loginCard {
+  width: min(420px, 100%);
+  background: rgba(0, 0, 0, 0.35);
+  border: 1px solid rgba(255, 255, 255, 0.10);
+  border-radius: 18px;
+  padding: 18px;
+  box-shadow: 0 20px 80px rgba(0, 0, 0, 0.35);
+}
+
+.loginCard__brand {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.loginCard__mark {
+  width: 18px;
+  height: 18px;
+  border-radius: 6px;
+  background: linear-gradient(135deg, rgba(168, 85, 247, 0.95), rgba(59, 130, 246, 0.9));
+  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.12);
+}
+
+.loginCard__title {
+  font-weight: 900;
+  font-size: 16px;
+  letter-spacing: 0.2px;
+}
+
+.loginCard__subtitle {
+  margin-top: 10px;
+  color: var(--muted);
+  font-size: 13px;
+}
+
+.loginForm {
+  margin-top: 16px;
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+}
+
+.loginForm__input {
+  width: 100%;
+}
+
+.loginForm__error {
+  color: var(--neg);
+  font-size: 12px;
+}
+
+.loginForm__actions {
+  margin-top: 6px;
+  display: flex;
+  justify-content: flex-end;
+}
+
 .shellHeader {
   background: rgba(0, 0, 0, 0.35);
   border-bottom: 1px solid rgba(255, 255, 255, 0.10);