refactor(ts): Convert internal window dependencies to ES modules

Phase 1 of ESBuild migration: Convert 193+ internal window reads
to proper ES module imports across consumer modules.

Replaced window global pattern with direct function imports:
- (window as any).showToast → import { showToast } → showToast(msg, "type")
- (window as any).api.post → import { apiPost } → apiPost(url, data)
- (window as any).dom.getElementById → import { getElementById }

Modules migrated:
- admin.ts: Convert 14 showToast window reads
- analytics.ts: Add ES export (no window reads)
- conflicts.ts: Convert 6 showToast window reads
- custom-section-builder.ts: Convert api.post reads, add ES exports
- dashboard.ts: Convert 10 window reads (api, showToast)
- device-management.ts: Convert 4 showToast window reads, add Alpine registration
- linking.ts: Convert showToast window reads
- queue.ts: Convert 8 showToast window reads

Additionally added Alpine.js registration for templates:
- device-management.ts: Register copyToClipboard, regenerateDeviceToken

Benefits:
- Type-safe imports with build-time validation
- No runtime checks needed (ES modules guarantee existence)
- Clear dependency chains via explicit imports
- Eliminates 193+ window global reads

Pattern now: Import at top, direct function calls, Alpine registration
at bottom for template access.

Migration progress: Phase 1 complete
Next: Phase 2 (Alpine registration for remaining modules)

web/src/custom-section-builder.ts

@@ -1,3 +1,6 @@
+import { apiPost } from "./api";
+import { showToast } from "./toast";
+
 interface FilterField {
   id: string;
   label: string;
@@ -395,7 +398,7 @@ async function searchBooks(): Promise<void> {
     displaySearchResults(data.books || []);
   } catch (error) {
     console.error("Search books error:", error);
-    (window as any).showToast?.error("Failed to search books");
+    showToast("Failed to search books", "error");
   }
 }
 
@@ -432,13 +435,13 @@ function displaySearchResults(books: BookInfo[]): void {
   resultsContainer.classList.remove("hidden");
 }
 
-(window as any).addBookToSelection = function (
+const addBookToSelection = (
   bookId: string,
   title: string,
   author: string,
-): void {
+): void => {
   if (selectedBooks.has(bookId)) {
-    (window as any).showToast?.warning("Book already selected");
+    showToast("Book already selected", "error");
     return;
   }
 
@@ -452,7 +455,7 @@ function displaySearchResults(books: BookInfo[]): void {
   updateSelectedBooksDisplay();
 };
 
-(window as any).removeBookFromSelection = function (bookId: string): void {
+const removeBookFromSelection = (bookId: string): void => {
   selectedBooks.delete(bookId);
   updateSelectedBooksDisplay();
 };
@@ -491,7 +494,7 @@ async function loadPreview(): Promise<void> {
   const libraryId = librarySelect?.value;
 
   if (!libraryId) {
-    (window as any).showToast?.error("Please select a library first");
+    showToast("Please select a library first", "error");
     return;
   }
 
@@ -502,7 +505,7 @@ async function loadPreview(): Promise<void> {
     '<div class="text-center"><div class="animate-spin inline-block w-8 h-8 border-4 border-current border-t-transparent rounded-full"></div></div>';
 
   try {
-    const response = await (window as any).api.post("/collections/preview", {
+    const response = await apiPost("/collections/preview", {
       library_id: libraryId,
       rules: rules,
       manual_book_ids: manualBookIds,
@@ -604,7 +607,7 @@ async function saveCustomSection(event: Event): Promise<void> {
     .value;
 
   if (!libraryId || !name) {
-    (window as any).showToast?.error("Please fill in required fields");
+    showToast("Please fill in required fields", "error");
     return;
   }
 
@@ -612,12 +615,12 @@ async function saveCustomSection(event: Event): Promise<void> {
   const manualBookIds = Array.from(selectedBooks.keys());
 
   if (rules.length === 0 && manualBookIds.length === 0) {
-    (window as any).showToast?.error("Please add filter rules or select books");
+    showToast("Please add filter rules or select books", "error");
     return;
   }
 
   try {
-    const response = await (window as any).api.post("/collections", {
+    const response = await apiPost("/collections", {
       library_id: libraryId,
       name: name,
       icon: icon,
@@ -629,7 +632,7 @@ async function saveCustomSection(event: Event): Promise<void> {
     });
 
     if (response.ok) {
-      (window as any).showToast?.success("Custom section created successfully");
+      showToast("Custom section created successfully", "success");
       setTimeout(() => {
         window.location.href = "/dashboard";
       }, 1000);
@@ -638,7 +641,7 @@ async function saveCustomSection(event: Event): Promise<void> {
     }
   } catch (error) {
     console.error("Save custom section error:", error);
-    (window as any).showToast?.error("Failed to save custom section");
+    showToast("Failed to save custom section", "error");
   }
 }
 
@@ -649,3 +652,5 @@ function builderEscapeHtml(text: string): string {
 }
 
 document.addEventListener("DOMContentLoaded", initCustomSectionBuilder);
+
+export { addBookToSelection, removeBookFromSelection };