feat: auth screen with auto-redirect, sync favorites/history with backend

.agents/skills/vercel-composition-patterns/rules/_sections.md

@@ -0,0 +1,29 @@
+# Sections
+
+This file defines all sections, their ordering, impact levels, and descriptions.
+The section ID (in parentheses) is the filename prefix used to group rules.
+
+---
+
+## 1. Component Architecture (architecture)
+
+**Impact:** HIGH  
+**Description:** Fundamental patterns for structuring components to avoid prop
+proliferation and enable flexible composition.
+
+## 2. State Management (state)
+
+**Impact:** MEDIUM  
+**Description:** Patterns for lifting state and managing shared context across
+composed components.
+
+## 3. Implementation Patterns (patterns)
+
+**Impact:** MEDIUM  
+**Description:** Specific techniques for implementing compound components and
+context providers.
+
+## 4. React 19 APIs (react19)
+
+**Impact:** MEDIUM  
+**Description:** React 19+ only. Don't use `forwardRef`; use `use()` instead of `useContext()`.