fix: import type + lazy singleton pour dagre et pptxgenjs (Turbopack build)

Co-authored-by: Cursor <cursoragent@cursor.com>

memento-note/lib/ai/tools/excalidraw.tool.ts

@@ -4,7 +4,16 @@ import { tool } from 'ai'
 import { z } from 'zod'
 import { toolRegistry } from './registry'
 import { prisma } from '@/lib/prisma'
-import dagre from 'dagre'
+// import type is erased at build time — Turbopack won't try to resolve the module
+import type dagreType from 'dagre'
+let _dagre: typeof dagreType | null = null
+async function getDagre(): Promise<typeof dagreType> {
+  if (!_dagre) {
+    const mod = await import('dagre')
+    _dagre = (mod.default ?? mod) as typeof dagreType
+  }
+  return _dagre
+}
 
 interface SimplifiedNode {
   id: string
@@ -504,12 +513,13 @@ function getNodeRenderSpec(node: SimplifiedNode, isCenter: boolean): NodeRenderS
   return { text: wrapped, fontSize, width, height }
 }
 
-function computeNodeLayoutForRankdir(
+async function computeNodeLayoutForRankdir(
   nodes: SimplifiedNode[],
   edges: SimplifiedEdge[],
   rankdir: 'LR' | 'TB',
   renderSpecs: Map<string, NodeRenderSpec>,
-): Map<string, NodeLayoutBox> {
+): Promise<Map<string, NodeLayoutBox>> {
+  const dagre = await getDagre()
   const graph = new dagre.graphlib.Graph()
   graph.setGraph({
     rankdir,
@@ -738,11 +748,11 @@ async function computeNodeLayout(
   const firstRankdir: 'LR' | 'TB' = (diagramType === 'org-chart') ? 'TB' : 'LR'
   const secondRankdir: 'LR' | 'TB' = firstRankdir === 'LR' ? 'TB' : 'LR'
 
-  const lrLayout = computeNodeLayoutForRankdir(nodes, edges, firstRankdir, renderSpecs)
+  const lrLayout = await computeNodeLayoutForRankdir(nodes, edges, firstRankdir, renderSpecs)
   const lrQuality = computeLayoutQuality(nodes, edges, lrLayout)
   const lrBounds = getLayoutBounds(lrLayout)
 
-  const tbLayout = computeNodeLayoutForRankdir(nodes, edges, secondRankdir, renderSpecs)
+  const tbLayout = await computeNodeLayoutForRankdir(nodes, edges, secondRankdir, renderSpecs)
   const tbQuality = computeLayoutQuality(nodes, edges, tbLayout)
   const tbBounds = getLayoutBounds(tbLayout)