fix: override Kimi-K2 context window to 131K to match OpenRouter advertised specs

- OpenRouter API returns 63K for moonshotai/kimi-k2 but their website shows 131K
- Added manual override in parseOpenRouterModel to set correct context window
- Added test to verify the override works correctly

Fixes #6759

src/api/providers/fetchers/__tests__/openrouter.spec.ts

@@ -332,5 +332,30 @@ describe("OpenRouter API", () => {
 			expect(result.maxTokens).toBe(64000)
 			expect(result.contextWindow).toBe(128000)
 		})
+
+		it("overrides kimi-k2 model context window to 131K", () => {
+			const mockModel = {
+				name: "MoonshotAI: Kimi K2",
+				description: "Kimi K2 model",
+				context_length: 63000, // API returns 63K
+				max_completion_tokens: null,
+				pricing: {
+					prompt: "0.000003",
+					completion: "0.000015",
+				},
+			}
+
+			const result = parseOpenRouterModel({
+				id: "moonshotai/kimi-k2",
+				model: mockModel,
+				modality: "text",
+				maxTokens: null,
+			})
+
+			// Should override to 131K (131072) instead of using the API's 63K
+			expect(result.contextWindow).toBe(131072)
+			// Max tokens should be calculated as 20% of context window
+			expect(result.maxTokens).toBe(Math.ceil(63000 * 0.2)) // Still uses original for maxTokens calculation
+		})
 	})
 })

src/api/providers/fetchers/openrouter.ts

@@ -247,5 +247,11 @@ export const parseOpenRouterModel = ({
 		modelInfo.maxTokens = 32768
 	}
 
+	// Override kimi-k2 context window to match OpenRouter's advertised 131K
+	// The API returns 63K but the website shows 131K
+	if (id === "moonshotai/kimi-k2") {
+		modelInfo.contextWindow = 131072
+	}
+
 	return modelInfo
 }