feat(api-nodes-pricing): add Nano-Banana-2 prices (#6781)

## Summary

Change pricing display for Nano Banana 1, and added pricing for Nano
Banana 2.

## Screenshots (if applicable)

<img width="2101" height="963" alt="image"
src="https://github.com/user-attachments/assets/78c922c6-f6d8-47c3-afeb-adf28deb5542"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6781-feat-api-nodes-pricing-add-Nano-Banana-2-prices-2b16d73d3650810a8e8dde8f01ba9f02)
by [Unito](https://www.unito.io)

Author: bigcat88

src/composables/node/useNodePricing.ts

@@ -1545,7 +1545,26 @@ const apiNodeCosts: Record<string, { displayPrice: string | PricingFunction }> =
       }
     },
     GeminiImageNode: {
-      displayPrice: '$0.03 per 1K tokens'
+      displayPrice: '~$0.039/Image (1K)'
+    },
+    GeminiImage2Node: {
+      displayPrice: (node: LGraphNode): string => {
+        const resolutionWidget = node.widgets?.find(
+          (w) => w.name === 'resolution'
+        ) as IComboWidget
+
+        if (!resolutionWidget) return 'Token-based'
+
+        const resolution = String(resolutionWidget.value)
+        if (resolution.includes('1K')) {
+          return '~$0.134/Image'
+        } else if (resolution.includes('2K')) {
+          return '~$0.134/Image'
+        } else if (resolution.includes('4K')) {
+          return '~$0.24/Image'
+        }
+        return 'Token-based'
+      }
     },
     // OpenAI nodes
     OpenAIChatNode: {
@@ -1829,6 +1848,7 @@ export const useNodePricing = () => {
       TripoTextureNode: ['texture_quality'],
       // Google/Gemini nodes
       GeminiNode: ['model'],
+      GeminiImage2Node: ['resolution'],
       // OpenAI nodes
       OpenAIChatNode: ['model'],
       // ByteDance

tests-ui/tests/composables/node/useNodePricing.test.ts

@@ -1763,7 +1763,7 @@ describe('useNodePricing', () => {
         const node = createMockNode('GeminiImageNode')
 
         const price = getNodeDisplayPrice(node)
-        expect(price).toBe('$0.03 per 1K tokens')
+        expect(price).toBe('~$0.039/Image (1K)')
       })
     })