feat: add private bookmark fetching with NIP-44 decryption

- Update ActiveAccount interface to include signer property
- Modify fetchBookmarks to handle both kind 10003 (public) and kind 30001 (private) bookmark lists
- Implement NIP-44 decryption for private bookmarks using applesauce SimpleSigner
- Support both public tags and encrypted private content in categorized bookmarks
- Maintain backward compatibility with existing public bookmark functionality

src/types/bookmarks.ts

@@ -40,4 +40,5 @@ export interface IndividualBookmark {
 
 export interface ActiveAccount {
   pubkey: string
+  signer?: any // SimpleSigner from applesauce
 }