feat(header): add smart sticky scroll animation and styling refinements

- Implement RAF-throttled smart sticky scroll interaction on app header
- Add flow-root BFC isolation, vertical margin, and mobile menu scroll container
- Update brand logo kicker hover color to primary accent (cobalt-dark)
- Fix theme script hydration warning with suppressHydrationWarning
- Add favicon.ico and icon.svg to resolve root /favicon.ico 404
- Add MAM orchestration guidelines, env generation script, and templates

refer_landing_page/app/globals.css

@@ -172,6 +172,14 @@ body {
   .draw-underline:hover {
     background-size: 100% 2px;
   }
+
+  /* Mobile menu scroll container for low-height / landscape viewports (F4) */
+  .mobile-menu-panel {
+    max-height: calc(100vh - 6rem);    /* Fallback: browsers without dvh support */
+    max-height: calc(100dvh - 6rem);   /* Modern: dynamic viewport height */
+    overflow-y: auto;
+    overscroll-behavior: contain;      /* Prevent chaining scroll to main page */
+  }
 }
 
 /* ==================================================================
@@ -217,6 +225,11 @@ body {
   [class*="animate-"] {
     animation: none !important;
   }
+  /* 스마트 스티키: 모션 줄임 사용자에게는 항상 펼친 상태 유지 */
+  header[data-smart-sticky] {
+    transform: none !important;
+    transition: none !important;
+  }
   html {
     scroll-behavior: auto;
   }