Add paginated responses (items/total/skip/limit) to:
- GET /api/data/stocks/{ticker}/prices (default limit=365)
- GET /api/data/etfs/{ticker}/prices (default limit=365)
- GET /api/portfolios/{id}/snapshots (default limit=100)
- GET /api/portfolios/{id}/transactions (default limit=50)
Frontend: update snapshot/transaction consumers to handle new response
shape, add "Load more" button to transaction table.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
