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

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

@@ -0,0 +1,24 @@
+---
+title: Rule Title Here
+impact: MEDIUM
+impactDescription: brief description of impact
+tags: composition, components
+---
+
+## Rule Title Here
+
+Brief explanation of the rule and why it matters.
+
+**Incorrect:**
+
+```tsx
+// Bad code example
+```
+
+**Correct:**
+
+```tsx
+// Good code example
+```
+
+Reference: [Link](https://example.com)