Fix token handling, modal behavior, and pagination

Multiple fixes and improvements:

- src/app/api/user/hardcover-shelves/[id]/route.ts: Make token testing more robust by using the existing shelf.apiToken when no new token is provided, attempt decryption only when needed, and gracefully fall back on decryption errors.
- src/components/ui/AddShelfModal.tsx: Simplify token handling by passing the trimmed token directly to addHardcover (remove client-side 'Bearer ' stripping).
- src/components/ui/ManageShelfModal.tsx: Stabilize form reset effect by depending on shelf?.id to avoid unnecessary re-renders when the shelf object changes identity.
- src/components/ui/Modal.tsx: Simplify modal rendering by removing the mounted state and createPortal usage, cleaning up imports and rendering directly.
- src/lib/services/hardcover-api.service.ts: Add a logger, introduce a MAX_PAGES cap and page counters to prevent unbounded pagination loops, and log/break when the API returns errors during pagination.

These changes improve reliability (token handling and pagination safety), reduce unnecessary renders, and simplify modal lifecycle.

src/components/ui/AddShelfModal.tsx

@@ -77,11 +77,7 @@ export function AddShelfModal({ isOpen, onClose }: AddShelfModalProps) {
         setRssUrl('');
       } else {
         const finalId = listType === 'status' ? `status-${statusId}` : customListId.trim();
-        let cleanedToken = apiToken.trim();
-        if (cleanedToken.toLowerCase().startsWith('bearer ')) {
-          cleanedToken = cleanedToken.slice(7).trim();
-        }
-        const shelf = await addHardcover(cleanedToken, finalId);
+        const shelf = await addHardcover(apiToken.trim(), finalId);
         setSuccessMessage(`Added list "${shelf.name}" successfully!`);
         setApiToken('');
         setCustomListId('');