A hit test asks the same area as the pointer, and the + menu is scrolled by the scaffold

Behaviors: "on a node" for an edge drop is the node's pointer area, which reaches a port radius past
its edge, so a drop on an input port at x = 0 is never a drop on empty canvas. Development: steps
pick an asset type with `pickAssetType()`, the way they open a tab with `openTab()`.

Behaviors.md

@@ -224,7 +224,10 @@ shown on the node and editable in the inspector.
   types this edge could reach at all, and the picked node arrives already wired; node and link go
   in as **one** undo step (`core/graph/dropTarget.ts` decides all of this, the canvas only draws
   it). The dangling edge stays on screen while that palette is up, so the connection being made is
-  still visible while its node is chosen.
+  still visible while its node is chosen. **"On a node" means the area the node's pointer events
+  use** (`NodeView.containsLocal`), which reaches a port radius past the left and right edge: an
+  input port sits at exactly the node's edge, so a drop that hits the port hits the node, and never
+  the empty canvas a hair beside it.
 - **A link can be hidden**, so a connection across the whole graph does not have to be drawn as a
   line across the whole graph. Right-click a port → *Hide link*; the curve is replaced by a short
   stub at each end, ending in a dot captioned with the node at the *other* end. The connection is

Development.md

@@ -73,6 +73,12 @@ not by clicking its name: since the tenth tab the row hides some of them at the
 and the helper goes through the `»` menu when it has to. Clicking the label directly took the
 whole suite down the day the Particles tab was added.
 
+The same holds for the **`+` menu**: it has one entry per asset type and scrolls past 320 px, so the
+last of them sit under the mask, where `locate` still finds an entry but a click on it lands on
+nothing. A step picks a type with `pickAssetType(t, 'Font')` from the same file, which scrolls it in
+first. The fourteenth type (Variables) pushed `Font` under that edge and took the font step down,
+because only the particles step had carried the workaround of its own.
+
 **A check that demands an exact number must be handed the number, not something it can be derived
 from.** The particle preview used to hold second 0.5 by computing the clock reading that *would* mean
 0.5 since the field started; the round trip through floating point misses by the last bit about one