Make texture and colour full kinds and drop the load-time migrations

- `Texture` and `Color` can be picked as a variable kind, a struct field
  kind and a declared port kind; a new `Texture` node hands a picture id
  into the graph. Declared, a texture is its bare id – the `$texture` tag
  stays a list-only thing.
- The `String` node is labelled "Text" like its kind; the type id stays.
- Whole-number inputs (`Item at`, `Set item`, `Sub list`, `Fill`,
  `Repeat`, `Substring`, `To text`) show no decimals (`int()` in shared.ts).
- All server projects are reseeded, so `legacyNodes.ts`,
  `migrateDeclaredLists` and the `ownerId` fallback go, with their tests.
- Note `reseed-because-of-list` moved to done/; new note `refactor-types`.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/core/graph/nested.ts

@@ -75,8 +75,14 @@ export function isTerminalNode(node: GraphNode): boolean {
   return isTerminalType(node.type);
 }
 
+/** A color or texture port carries the field that edits it; the graph itself sees a number or a text. */
 export function portDefOf(port: DeclaredPort): PortDef {
-  return { key: port.key, label: port.key, type: declaredPortType(port.kind) };
+  const def: PortDef = { key: port.key, label: port.key, type: declaredPortType(port.kind) };
+  if (port.kind === 'color')
+    return { ...def, field: { key: port.key, label: port.key, kind: 'color', default: 0 } };
+  if (port.kind === 'texture')
+    return { ...def, field: { key: port.key, label: port.key, kind: 'texture', default: '' } };
+  return def;
 }
 
 /** The ports the start (or end) node of `graph` declares, as seen from a node calling it. */