feat: add deepseek-coder model to DeepSeek provider

- Added deepseek-coder model configuration with 8K max output tokens
- Added test coverage for the new model
- Fixes issue where users could not select deepseek-coder model

Fixes #7773

Author: roomote

packages/types/src/providers/deepseek.ts

@@ -17,6 +17,17 @@ export const deepSeekModels = {
 		cacheReadsPrice: 0.07, // $0.07 per million tokens (cache hit) - Updated Sept 5, 2025
 		description: `DeepSeek-V3 achieves a significant breakthrough in inference speed over previous models. It tops the leaderboard among open-source models and rivals the most advanced closed-source models globally.`,
 	},
+	"deepseek-coder": {
+		maxTokens: 8192, // 8K max output
+		contextWindow: 128_000,
+		supportsImages: false,
+		supportsPromptCache: true,
+		inputPrice: 0.56, // $0.56 per million tokens (cache miss) - Updated Sept 5, 2025
+		outputPrice: 1.68, // $1.68 per million tokens - Updated Sept 5, 2025
+		cacheWritesPrice: 0.56, // $0.56 per million tokens (cache miss) - Updated Sept 5, 2025
+		cacheReadsPrice: 0.07, // $0.07 per million tokens (cache hit) - Updated Sept 5, 2025
+		description: `DeepSeek-Coder-V3 is specifically optimized for code generation, completion, and understanding tasks. It excels at programming challenges across multiple languages.`,
+	},
 	"deepseek-reasoner": {
 		maxTokens: 65536, // 64K max output for reasoning mode
 		contextWindow: 128_000,

src/api/providers/__tests__/deepseek.spec.ts

@@ -160,6 +160,20 @@ describe("DeepSeekHandler", () => {
 			expect(model.info.supportsPromptCache).toBe(true) // Should be true now
 		})
 
+		it("should return correct model info for deepseek-coder", () => {
+			const handlerWithCoder = new DeepSeekHandler({
+				...mockOptions,
+				apiModelId: "deepseek-coder",
+			})
+			const model = handlerWithCoder.getModel()
+			expect(model.id).toBe("deepseek-coder")
+			expect(model.info).toBeDefined()
+			expect(model.info.maxTokens).toBe(8192) // deepseek-coder has 8K max
+			expect(model.info.contextWindow).toBe(128_000)
+			expect(model.info.supportsImages).toBe(false)
+			expect(model.info.supportsPromptCache).toBe(true)
+		})
+
 		it("should return correct model info for deepseek-reasoner", () => {
 			const handlerWithReasoner = new DeepSeekHandler({
 				...mockOptions,