fix migration exports (#3586)

We're missing the export for `createShapePropsMigrationIds`, so lets add
it. This also fixes some other bits that were used in examples but not
exported properly from tldraw.

### Change Type

- [x] `sdk` — Changes the tldraw SDK
- [x] `bugfix` — Bug fix

### Release Notes

- Expose `createShapePropsMigrationIds`, `defaultEditorAssetUrls`,
`PORTRAIT_BREAKPOINT`, `useDefaultColorTheme`, & `getPerfectDashProps`

scripts/lib/eslint-plugin.ts

@@ -59,4 +59,48 @@ exports.rules = {
 		},
 		defaultOptions: [],
 	}),
+	'no-internal-imports': ESLintUtils.RuleCreator.withoutDocs({
+		create(context) {
+			return {
+				ImportDeclaration(node) {
+					const path = node.source.value
+
+					const parts = path.split('/')
+
+					switch (parts[0]) {
+						case 'tldraw':
+							// 'tldraw'
+							if (parts.length === 1) return
+							// 'tldraw/**/*.css'
+							if (path.endsWith('.css')) return
+							break
+						case '@tldraw':
+							// '@tldraw/*'
+							if (parts.length === 2) return
+							// '@tldraw/**/*.css'
+							if (path.endsWith('.css')) return
+							// '@tldraw/assets/*'
+							if (parts[1] === 'assets' && parts.length === 3) return
+							break
+						default:
+							return
+					}
+
+					context.report({
+						messageId: 'internal',
+						node: node.source,
+						data: { path },
+					})
+				},
+			}
+		},
+		meta: {
+			messages: {
+				internal: "Don't import from internal tldraw source ({{path}})",
+			},
+			type: 'problem',
+			schema: [],
+		},
+		defaultOptions: [],
+	}),
 }