feat: Add new Alpine.js component TypeScript files

Extracted inline JavaScript from templates into proper TypeScript modules:

- api-explorer-docs.ts: API explorer page functionality
- collection-rules.ts: Collection rules management page
- index.ts: Homepage theme and auth redirect
- login.ts: Login page theme initialization
- profile-modal.ts: Profile modal close and escape key
- profile.ts: Profile page delete account
- register.ts: Registration page theme init
- toast-error.ts: Error toast with retry button
- unlinked_books.ts: Unlinked books management page

Each file:
- Uses ES imports (showToast, getToken, etc.)
- Has proper TypeScript types
- Registers with Alpine.js via Alpine.global()
- Uses async/await for API calls

web/src/index.ts

@@ -0,0 +1,50 @@
+import { Alpine } from "./alpine";
+import { applyTheme } from "./theme";
+import { getToken } from "./storage";
+
+function initIndexTheme(): void {
+  // Progressive enhancement: check localStorage immediately
+  const savedTheme = localStorage.getItem("theme");
+  if (savedTheme && savedTheme !== "tokyo-night") {
+    applyTheme(savedTheme);
+  }
+}
+
+function changeTheme(): void {
+  const select = document.getElementById("theme-select") as HTMLSelectElement;
+  if (!select) return;
+
+  const newTheme = select.value;
+  applyTheme(newTheme);
+
+  // Save to localStorage
+  localStorage.setItem("theme", newTheme);
+}
+
+async function checkAuthRedirect(): Promise<void> {
+  const token = getToken();
+  if (!token) return;
+
+  try {
+    const response = await fetch("/api/auth/profile", {
+      headers: {
+        Authorization: `Bearer ${token}`,
+      },
+    });
+
+    if (response.ok) {
+      // Token is valid, redirect to dashboard
+      window.location.href = "/dashboard";
+    }
+  } catch (error) {
+    console.error("Failed to check auth", error);
+  }
+}
+
+export { changeTheme, checkAuthRedirect, initIndexTheme };
+
+Alpine.global("index", {
+  changeTheme,
+  checkAuthRedirect,
+  initIndexTheme,
+});