Apply derivedSymbolData sizes on import

Figma pre-computes child dimensions for each combination of
component property values and stores them in derivedSymbolData.
Apply these size overrides using the same guidPath resolution
as symbolOverrides so containers shrink correctly when boolean
properties hide children.

packages/core/src/kiwi/instance-overrides.ts

@@ -29,6 +29,12 @@ interface ComponentPropAssignment {
   value: { boolValue?: boolean; textValue?: string }
 }
 
+interface DerivedSymbolOverride {
+  guidPath?: { guids?: GUID[] }
+  size?: { x: number; y: number }
+  [key: string]: unknown
+}
+
 export interface InstanceNodeChange {
   type?: string
   guid?: GUID
@@ -37,6 +43,7 @@ export interface InstanceNodeChange {
   componentPropDefs?: ComponentPropDef[]
   componentPropRefs?: ComponentPropRef[]
   componentPropAssignments?: ComponentPropAssignment[]
+  derivedSymbolData?: DerivedSymbolOverride[]
 }
 
 /**
@@ -223,6 +230,31 @@ export function populateAndApplyOverrides(
     }
   }
 
+  // Apply derivedSymbolData — pre-computed sizes for the current set of
+  // component property values. Uses the same guidPath resolution as
+  // symbolOverrides.
+  function applyDerivedSymbolData() {
+    for (const [ncId, nc] of changeMap) {
+      if (nc.type !== 'INSTANCE') continue
+      const derived = nc.derivedSymbolData
+      if (!derived?.length) continue
+
+      const nodeId = guidToNodeId.get(ncId)
+      if (!nodeId) continue
+
+      for (const d of derived) {
+        const guids = d.guidPath?.guids
+        if (!guids?.length) continue
+        if (!d.size) continue
+
+        const targetId = resolveOverrideTarget(nodeId, guids)
+        if (!targetId) continue
+
+        graph.updateNode(targetId, { width: d.size.x, height: d.size.y })
+      }
+    }
+  }
+
   // Apply overrides from each INSTANCE's symbolData
   const overriddenNodes = new Set<string>()
 
@@ -276,6 +308,7 @@ export function populateAndApplyOverrides(
 
   applySymbolOverrides()
   applyComponentProperties()
+  applyDerivedSymbolData()
 
   if (overriddenNodes.size === 0) return