Move a large graph instead of drawing it again (#292)

In a graph of many nodes the frame rate dropped while panning, and
more so while one node was dragged. Every pointer move rebuilt every
box, every text and every curve, and a drag also announced a changed
project, so the panels rebuilt along with it.

- Panning and zooming move the picture. GraphCanvas.applyView sets
  position and scale and draws anew only the grid and the rubber
  band. It used to call redraw().
- A node draws its box and makes its texts only when what they show
  has changed. NodeView keeps a signature of what redraw reads and
  one of what rebuildTexts reads, and returns early while they hold.
- A drag does not announce a changed project. GraphDrags writes the
  model on every pointer move and asks the canvas once a frame to
  follow (GraphCanvasHost.moved). state.preview() waits for the
  command of the release.
- Nodes outside the picture are not drawn. inView in graphView.ts is
  the rule, cull() applies it after every redraw and every change of
  the view.
- The graph is a render group, and box and pins go into the batch.
  The mask sits on a container above the group, on the group itself
  it would be panned and zoomed along.
- The rubber band and the drop mark of a dragged behavior are drawn
  on their own (drawBand), without a redraw of the graph.

Measured in the CI image with 388 nodes and 540 links, fitted to the
canvas, 240 pointer moves 16 ms apart:

- Pan, script per move: 25.2 ms before, 2.0 ms after
- Pan: 4.4 frames per second before, 18.7 after
- Drag a node: 2.7 frames per second before, 22.4 after
- The still picture: 9 frames per second before, 21 after

Not solved: the still picture of such a graph stays at 21 frames per
second in the test browser. What is left is the drawing itself, and
the frame rates are those of that browser, not of a desktop GPU.

Tests:
- Gate on melektaus-atx: 207 files, 3121 tests (3114 + 7), exit 0
- e2e 4,6,18,19,20,23,24,26,28,31,36,43,51,53 on melektaus-atx: 542
  pass, 1 fail. The fail is module 51 after module 43, an order the
  suite does not have, and it fails the same way without this
  change. Module 51 alone: 12 checks, all pass.
- No full run and no smokes. The sum of 1660 (1656 + 4) is reckoned,
  and the CI workflow is switched off.
- Seven unit tests: six for inView in tests/editor/graph-view.test.ts
  and one in frame-preview.test.ts
- Four e2e checks in block 6z-xii of module 06: pan, drag, zoom in
  and fit, a changed value
- Seven browser counter-probes fail 2 to 3 checks each

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/editor/debug/graphHooks.ts

@@ -58,6 +58,9 @@ export function graphHooks({ state, editor }: HookContext) {
       snapping: () => graphEditor.canvas.snapEnabled,
       snapButton: () => snapButton(graphEditor.snap),
       zoom: () => graphEditor.canvas.zoomLevel,
+      /** Nodes left in the picture, and how often texts, boxes and links were really made (#292). */
+      nodesDrawn: () => graphEditor.canvas.nodesDrawn(),
+      made: () => graphEditor.canvas.partsMade(),
       crumbs: () => graphEditor.breadcrumb.crumbsDrawn(),
     },
     stateMachine: {