feat(insta): replace Blog Lab page with Insta cards UI

/blog-lab → /insta route. New InstaCards page consumes insta-lab API
(news/keywords/slates + 10-page card preview + prompt template editor).
25개 blog-marketing API helper 제거, 13개 insta helper 추가.

src/routes.jsx

@@ -9,7 +9,7 @@ import {
     IconMusic,
     IconLab,
     IconTodo,
-    IconBlogMarketing,
+    IconInsta,
     IconPortfolio,
 } from './components/Icons';
 
@@ -26,7 +26,7 @@ const SwordStream = lazy(() => import('./pages/effect-lab/SwordStream'));
 const DayCalc = lazy(() => import('./pages/effect-lab/DayCalc'));
 const Todo = lazy(() => import('./pages/todo/Todo'));
 const MusicStudio = lazy(() => import('./pages/music/MusicStudio'));
-const BlogMarketing = lazy(() => import('./pages/blog-marketing/BlogMarketing'));
+const InstaCards = lazy(() => import('./pages/insta/InstaCards'));
 const Portfolio = lazy(() => import('./pages/portfolio/Portfolio'));
 
 export const navLinks = [
@@ -103,13 +103,13 @@ export const navLinks = [
         accent: '#f43f5e',
     },
     {
-        id: 'blog-lab',
-        label: 'Blog Lab',
-        path: '/blog-lab',
-        subtitle: 'MONETIZE',
-        description: 'AI 블로그 마케팅으로 수익을 만드는 연구소',
-        icon: <IconBlogMarketing />,
-        accent: '#10b981',
+        id: 'insta',
+        label: 'Insta',
+        path: '/insta',
+        subtitle: 'CARD FEED',
+        description: '뉴스에서 키워드 발굴 → AI 카드 10장 자동 생성 → 인스타 업로드',
+        icon: <IconInsta />,
+        accent: '#ec4899',
     },
     {
         id: 'todo',
@@ -190,8 +190,8 @@ export const appRoutes = [
         element: <MusicStudio />,
     },
     {
-        path: 'blog-lab',
-        element: <BlogMarketing />,
+        path: 'insta',
+        element: <InstaCards />,
     },
     {
         path: 'todo',