Chore: Port over SeriesDetail (WIP Panels)

src/lib/components/shared/manga/MigrateModal.svelte

@@ -0,0 +1,14 @@
+<script lang="ts">
+  let { onClose, ...rest }: { onClose?: () => void; [k: string]: any } = $props()
+</script>
+
+<div class="stub-panel">
+  <button class="stub-close" onclick={onClose}>✕</button>
+  <p class="stub-label">MigrateModal</p>
+</div>
+
+<style>
+  .stub-panel  { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px; padding: 32px; min-width: 240px; }
+  .stub-close  { align-self: flex-end; background: none; border: none; cursor: pointer; color: var(--text-muted); font-size: 16px; }
+  .stub-label  { color: var(--text-faint); font-size: var(--text-sm); }
+</style>