refactor: update main.ts imports for page-specific bookshelf loading

Change from global to page-specific JavaScript loading:

Remove:
- import "./bookshelf" (loaded globally on every page)

Add:
- import "./bookPicker" (needed globally for collections)

This change supports page-specific script loading strategy:
- Bookshelf: Loaded via <script> tag in bookshelf.templ only
- BookPicker: Loaded globally for collections page usage

Reduces JavaScript bundle size for pages that don't need bookshelf.
Matches SSR-first principle of progressive enhancement.

web/src/main.ts

@@ -6,7 +6,7 @@ import "./api";
 import "./analytics";
 import "./api-explorer";
 import "./api-explorer-docs";
-import "./bookshelf";
+import "./bookPicker";
 import "./collection-rules";
 import "./collections";
 import "./conflicts";