- ReaderView: complete rewrite with CSS styling, headers, attachments, zoom, find, dark mode, image blocking
- Categories: DAO + UI tree widget with colors, nested categories, assignment
- Rules engine: DAO + evaluation + actions (move, mark read, flag, delete, category, forward)
- Templates: DAO + editor + manager with variables support
- Signatures: DAO + manager + auto-per-account + manual selector in compose
- ComposeView: signature combo, template selector, auto-signature on new email
- MainWindow: frameless with rounded corners, 1px border, resize from edges, no status bar
- Database: new tables (Category, MailCategory, Rule, Template, Signature) with indexes
- Changed EmailListModel from QAbstractListModel to QAbstractTableModel
- Added columnCount() returning 3 columns (Subject, Sender, Date)
- Added headerData() for column headers (Asunto, De, Fecha)
- Modified data() to handle Qt::DisplayRole per column index
- Updated MailListView::setModel() to use column indices instead of role-based column hiding
- Added proper column resize modes (Stretch for Subject/Sender, ResizeToContents for Date)
- Default sort by Date column descending
javier