[cyenite]

Summary

• Shift snapping, as in TradingView. Holding Shift while placing or dragging a line's point snaps it level, upright or to 45 degrees from the previous point, and ignores the magnet. Shift while dragging a whole drawing moves it only sideways or only up and down (after 10px). Ctrl still turns the magnet on or off.
• Panning over drawings from higher timeframes. Drawing fills (channels, Fibonacci zones, rectangles, circles and similar) are now backgrounds the mouse passes through, as in TradingView, so dragging inside a channel drawn on a higher timeframe pans the chart instead of moving the channel. Drawings are grabbed by their lines; position tools and text boxes still pick up by their body.
• Tabs are now "Layouts". The + buttons and Window > New Layout offer Blank Layout or Copy of ... an open layout, which copies its charts, drawings, indicators and settings with fresh ids. Right-clicking a layout offers Duplicate Layout. Only the UI text changed; saved profiles load unchanged. The grid submenu is now Layout Setup, matching the toolbar button.

Test plan

• npm run typecheck
• npm test (706 pass), with new tests for background hit-testing, 45-degree alignment and layout copies
• npm run build
• Real mouse input in the Electron harness with the mock backend: a drag inside a parallel channel panned the view and left the channel unchanged; Shift-drawn lines came out level (equal prices with the strong magnet on), at 45 degrees (144 x 144 px) and upright (equal times); a Shift-dragged line kept its price; a copied layout showed the original's drawings