Render through a desynchronized WebGL context by default

Measured click-to-paint was 72-77 ms, of which the editor itself spends
under 4 ms; the rest is the finished frame waiting in the compositor
queue. A desynchronized context bypasses it (16-18 ms in the same probe).
Pixi has no option for it, so main.ts builds the WebGL2 context itself.
The mode may tear on some drivers; ?vsync falls back to Pixi's own
context.

__gm.lowLatency() reports the attributes the browser actually granted,
and a graph-step check pins that the mode stays on.

Also adds the todo note graph-node-collapse-width.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

todo-notes/graph-node-collapse-width.md

@@ -0,0 +1,2 @@
+man kann ja nun graph nodes zusammenklappen.
+hier soll auch die breite veringert werden auf die titeltext breite wenn möglich?