Let a variable hold a list

A variable could only be a number, a text or a yes/no, so every set of values had
to be smuggled through a string - which is where Tetris got its unreadable
"03066326048763714" colours from. A list is now a value of its own, with an item
kind (number, text, yes/no, colour) that decides how the inspector reads the one
comma-separated line it is typed as, and eight nodes to work with: List, Fill,
Count, Item at, Set item, Sub list, Join lists, Index of.

Two traps came with it. An array is typeof 'object', so every place that told a
value from an entity had to learn the difference, or a list would have been
passed around as a game object. And a value was compared by identity in three
places - with lists that marks everything as an overridden property after each
reload, so those comparisons now compare contents.

There is no list of objects: a list is written to the project file and an object
is a live handle that no reload survives. A set of objects stays a list of names.

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

src/core/graph/nodes/shared.ts

@@ -10,6 +10,7 @@ export const num = (key: string, label = key): PortDef => ({ key, label, type: '
 export const bool = (key: string, label = key): PortDef => ({ key, label, type: 'boolean' });
 export const str = (key: string, label = key): PortDef => ({ key, label, type: 'string' });
 export const obj = (key: string, label = key): PortDef => ({ key, label, type: 'object' });
+export const list = (key: string, label = key): PortDef => ({ key, label, type: 'list' });
 export const any = (key: string, label = key): PortDef => ({ key, label, type: 'any' });
 
 export const withDefault = (port: PortDef, value: PropertyValue): PortDef => ({ ...port, default: value });