Replace scattered inline tooltip implementations across canvas_view,
custom_shape_menu, layers_panel, batch_preview_manager, and notifications
with a single shared TooltipManager class.
- New src/utils/tooltip_manager.ts (and compiled js/utils/tooltip_manager.js)
provides observeRoot/bindTooltips/setTooltip/showTooltip/hideTooltip API
- Migrate title attributes to data-tooltip and normalize via MutationObserver
- Rename tooltip CSS from .lf-painter-tooltip/.lf-layerforge-tooltip to
.lf-global-tooltip and raise z-index to 1000001
- Remove duplicate matting-specific tooltip styles from canvas_view.css
- Update generated js/ outputs to match src/ changes
Dariusz L