feat(ts): centralized library storage with cookie-based SSR support

- storage.ts: Centralize ALL_LIBRARIES = "__all__" sentinel constant.
  setSelectedLibrary() now writes both localStorage and a cookie
  (selectedLibrary, Path=/, SameSite=Lax, max-age=365d). The
  sentinel "__all__" is used in both storage mediums — empty strings
  are never stored. getSelectedLibrary() maps __all__ back to "".
  Cookie enables server-side rendering to read the stored library
  selection without access to localStorage.

- library-switcher.ts: Import ALL_LIBRARIES and setSelectedLibrary/
  getSelectedLibrary from storage.ts instead of managing localStorage
  directly. Remove local constants.

- dashboard.ts: Remove duplicate localStorage.setItem call that was
  overwriting the __all__ sentinel with raw empty string. Fix
  reloadPage() and scan-complete handler to work with empty libraryId.
  openDashboardSettings/saveDashboardSettings show clear messages for
  All Libraries mode.

- collections.ts: Remove library switcher initialization from the
  collections list page — the list page no longer has a switcher.

- series.ts: Rewrite to use initLibrarySwitcher from library-switcher
  module and switchWithTransition for navigation. Series card links
  no longer include library_id in their URLs.

- bookshelf.ts: Autocomplete fetch calls handle empty libraryId
  correctly for All Libraries mode.

- search.ts, collection-rules.ts: Use setSelectedLibrary() and
  getSelectedLibrary() from storage.ts instead of direct localStorage
  access.

web/src/series.ts

@@ -1,6 +1,6 @@
 import { Alpine } from "./alpine";
 import { showToast } from "./toast";
-import { setSelectedLibrary } from "./storage";
+import { initLibrarySwitcher, switchWithTransition } from "./library-switcher";
 
 interface SeriesItem {
   name: string;
@@ -10,8 +10,8 @@ interface SeriesItem {
   last_entry_at: string;
 }
 
-function renderSeriesCard(series: SeriesItem, libraryId: string): string {
-  const href = `/series/detail?name=${encodeURIComponent(series.name)}&library_id=${libraryId}`;
+function renderSeriesCard(series: SeriesItem): string {
+  const href = `/series/detail?name=${encodeURIComponent(series.name)}`;
   const coverCount = series.cover_paths.length;
   const coverClass = `cover-count-${coverCount}`;
 
@@ -58,17 +58,18 @@ function renderSeriesContent(
       </main>`;
   }
 
-  const cardsHtml = seriesList.map((s) => renderSeriesCard(s, libraryId)).join("");
+  const cardsHtml = seriesList.map((s) => renderSeriesCard(s)).join("");
 
   let paginationHtml = "";
   if (totalPages > 1) {
+    const libParam = libraryId ? `library_id=${libraryId}&` : "";
     const prevLink =
       currentPage > 1
-        ? `<a href="/series?library_id=${libraryId}&page=${currentPage - 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">← Previous</a>`
+        ? `<a href="/series?${libParam}page=${currentPage - 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">← Previous</a>`
         : "";
     const nextLink =
       currentPage < totalPages
-        ? `<a href="/series?library_id=${libraryId}&page=${currentPage + 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">Next →</a>`
+        ? `<a href="/series?${libParam}page=${currentPage + 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">Next →</a>`
         : "";
     paginationHtml = `
       <div class="flex justify-center items-center gap-4 mt-8">
@@ -89,19 +90,10 @@ function renderSeriesContent(
 }
 
 async function switchLibrary(libraryId: string): Promise<void> {
-  const container = document.getElementById("series-container") as HTMLElement;
-  const loading = document.getElementById("loading-spinner") as HTMLElement;
-
-  if (!container || !loading) return;
-
-  try {
-    container.classList.add("opacity-0", "transition-opacity", "duration-150");
-    await new Promise((resolve) => setTimeout(resolve, 150));
-
-    loading.classList.remove("hidden");
-
+  await switchWithTransition("series-container", async () => {
+    const param = libraryId ? `library_id=${libraryId}&` : "";
     const response = await fetch(
-      `/api/series?library_id=${libraryId}&limit=24&offset=0`,
+      `/api/series?${param}limit=24&offset=0`,
       {
         headers: {
           Authorization: `Bearer ${localStorage.getItem("token")}`,
@@ -119,55 +111,17 @@ async function switchLibrary(libraryId: string): Promise<void> {
     const total: number = data.total || 0;
     const totalPages = Math.max(1, Math.ceil(total / 24));
 
-    container.innerHTML = renderSeriesContent(seriesList, libraryId, totalPages, 1);
-    setSelectedLibrary(libraryId);
-  } catch (error) {
-    showToast("Failed to load series", "error");
-    console.error("Switch library error:", error);
-  } finally {
-    loading.classList.add("hidden");
-
-    container.classList.remove("duration-150");
-    container.classList.add("duration-300");
-    void container.offsetHeight;
-    container.classList.remove("opacity-0");
-
-    setTimeout(() => {
-      container.classList.remove("transition-opacity", "duration-300");
-    }, 300);
-  }
+    const container = document.getElementById("series-container");
+    if (container) {
+      container.innerHTML = renderSeriesContent(seriesList, libraryId, totalPages, 1);
+    }
+  });
 }
 
 Alpine.data("seriesPage", () => ({
   initSeriesPage() {
-    const librarySelect = document.getElementById(
-      "library-select",
-    ) as HTMLSelectElement;
-    if (librarySelect) {
-      librarySelect.addEventListener("change", () => {
-        if (librarySelect.value) {
-          switchLibrary(librarySelect.value);
-        }
-      });
-    }
-  },
-}));
-
-Alpine.data("seriesDetailPage", () => ({
-  initSeriesDetailPage() {
-    const librarySelect = document.getElementById(
-      "library-select",
-    ) as HTMLSelectElement;
-    if (librarySelect) {
-      librarySelect.addEventListener("change", () => {
-        if (librarySelect.value) {
-          const url = new URL(window.location.href);
-          const currentLib = url.searchParams.get("library_id");
-          if (currentLib === librarySelect.value) return;
-          url.searchParams.set("library_id", librarySelect.value);
-          window.location.href = url.toString();
-        }
-      });
-    }
+    initLibrarySwitcher({
+      onSwitch: switchLibrary,
+    });
   },
 }));