fix(models): update GPT Luna pricing

Author: ericyangpan

manifests/models/gpt-5-6-luna.json

@@ -57,10 +57,15 @@
     {
       "url": "https://openai.com/index/gpt-5-6",
       "title": "GPT-5.6: Frontier intelligence that scales with your ambition",
-      "fields": ["name", "description", "releaseDate", "lifecycle", "tokenPricing"]
+      "fields": ["name", "description", "releaseDate", "lifecycle"]
+    },
+    {
+      "url": "https://developers.openai.com/api/docs/pricing",
+      "title": "OpenAI API pricing",
+      "fields": ["tokenPricing"]
     }
   ],
-  "lastVerifiedAt": "2026-07-20",
+  "lastVerifiedAt": "2026-07-31",
   "verifiedBy": "codex-agent",
   "confidence": "high",
   "websiteUrl": "https://openai.com",
@@ -78,16 +83,33 @@
         "currency": "USD",
         "region": "global",
         "serviceTier": "standard",
-        "effectiveFrom": null,
+        "effectiveFrom": "2026-07-31",
         "effectiveTo": null,
         "tiers": [
           {
-            "condition": null,
+            "condition": {
+              "metric": "inputTokens",
+              "min": 1,
+              "max": 272000
+            },
+            "rates": {
+              "input": 0.2,
+              "output": 1.2,
+              "cacheRead": 0.02,
+              "cacheWrite": 0.25
+            }
+          },
+          {
+            "condition": {
+              "metric": "inputTokens",
+              "min": 272001,
+              "max": 922000
+            },
             "rates": {
-              "input": 1,
-              "output": 6,
-              "cacheRead": 0.1,
-              "cacheWrite": null
+              "input": 0.4,
+              "output": 1.8,
+              "cacheRead": 0.04,
+              "cacheWrite": 0.5
             }
           }
         ]

tests/model-price-intelligence-index.test.ts

@@ -40,6 +40,17 @@ describe('model price-intelligence index', () => {
     }
   })
 
+  it('uses the reduced GPT-5.6 Luna short-context price', () => {
+    const luna = modelPriceIntelligencePoints.find(point => point.modelId === 'gpt-5-6-luna')
+
+    expect(luna).toMatchObject({
+      inputPrice: 0.2,
+      outputPrice: 1.2,
+      pricingSource: 'official',
+    })
+    expect(luna?.blendedPrice).toBeCloseTo(0.3)
+  })
+
   it('uses reviewed USD API prices when the catalog offer is not directly comparable', () => {
     const fallbackPoints = modelPriceIntelligencePoints.filter(
       point => point.pricingSource === 'reference'