fix(canvas): harmonize prompt model defaults for edge insertions

components/canvas/__tests__/use-canvas-edge-insertions.test.tsx

@@ -223,7 +223,7 @@ describe("useCanvasEdgeInsertions", () => {
         label: "Prompt",
         width: 320,
         height: 220,
-        defaultData: { prompt: "", model: "", aspectRatio: "1:1" },
+        defaultData: { prompt: "", aspectRatio: "1:1" },
       } as CanvasNodeTemplate);
     });
 
@@ -268,7 +268,7 @@ describe("useCanvasEdgeInsertions", () => {
         label: "Prompt",
         width: 320,
         height: 220,
-        defaultData: { prompt: "", model: "", aspectRatio: "1:1" },
+        defaultData: { prompt: "", aspectRatio: "1:1" },
       } as CanvasNodeTemplate);
     });
 
@@ -319,7 +319,7 @@ describe("useCanvasEdgeInsertions", () => {
         label: "Prompt",
         width: 320,
         height: 220,
-        defaultData: { prompt: "", model: "", aspectRatio: "1:1" },
+        defaultData: { prompt: "", aspectRatio: "1:1" },
       } as CanvasNodeTemplate);
     });
 
@@ -332,7 +332,7 @@ describe("useCanvasEdgeInsertions", () => {
       height: 220,
       data: {
         prompt: "",
-        model: "",
+        model: "google/gemini-2.5-flash-image",
         aspectRatio: "1:1",
         canvasId: "canvas-1",
       },
@@ -650,7 +650,7 @@ describe("useCanvasEdgeInsertions", () => {
         label: "Prompt",
         width: 320,
         height: 220,
-        defaultData: { prompt: "", model: "", aspectRatio: "1:1" },
+        defaultData: { prompt: "", model: "google/gemini-2.5-flash-image", aspectRatio: "1:1" },
       } as CanvasNodeTemplate);
     });
 

lib/canvas-node-templates.ts

@@ -18,7 +18,7 @@ export const CANVAS_NODE_TEMPLATES = [
     label: "Prompt",
     width: 320,
     height: 220,
-    defaultData: { prompt: "", model: "", aspectRatio: "1:1" },
+    defaultData: { prompt: "", model: "google/gemini-2.5-flash-image", aspectRatio: "1:1" },
   },
   {
     type: "video-prompt",

lib/canvas-utils.ts

@@ -235,7 +235,11 @@ export const NODE_DEFAULTS: Record<
 > = {
   image: { width: 280, height: 200, data: {} },
   text: { width: 256, height: 120, data: { content: "" } },
-  prompt: { width: 288, height: 220, data: { prompt: "", aspectRatio: "1:1" } },
+  prompt: {
+    width: 288,
+    height: 220,
+    data: { prompt: "", model: "google/gemini-2.5-flash-image", aspectRatio: "1:1" },
+  },
   "video-prompt": {
     width: 288,
     height: 220,