Changed: diagram toolbar + interaction modes (Pointer / Select / Grab / Space)

Changed: diagram toolbar and interaction modes Added a footer toolbar and removed the following actions from the main diagram toolbar: Undo / Redo Clipboard actions Alignment tools Trash Mode controls: Pointer (default), Select multiple, Grab, Space Updated: Pointer mode Clicking on the canvas now retains pointer (no implicit grab/pan), matching behavior over pools. When Pointer is active, the toolbar correctly reflects Pointer selected. Updated: Select tool (multi-select) Activate Click Select in the toolbar. Hold CMD / CTRL and drag to select. Deactivate Click Pointer, Grab, Space, or any other toolbar action. Release CMD / CTRL (if activated via shortcut). Press and release CMD / CTRL (if activated via toolbar). If activated via toolbar: when items are selected and the mouse button is released. Any other keyboard shortcut. Post-condition Pointer mode is automatically reactivated in the toolbar. Updated: Grab tool Activate Hold SPACE. Click Grab in the toolbar. Grab is standby by default; mouse down engages grab, mouse up returns to standby. Deactivate Release SPACE. Click Pointer, Select, Space, or any other toolbar action. Any other keyboard shortcut. Post-condition Pointer mode is automatically reactivated in the toolbar. Updated: Space tool Activate Press S. Click Space in the toolbar. Remains active until deactivated. Deactivate Press S again → enable Pointer. Click Pointer, Select, Grab, or any other toolbar action. Any other keyboard shortcut. Left click (without drag). Shortcut overrides while Space is active S → Pointer SPACE → Grab CMD → Grab Post-condition Pointer mode is automatically reactivated in the toolbar.