tests: Implement MockLLMProvider for tier 2 integration tests

packages/llm/src/index.ts

@@ -1,3 +1,4 @@
 export * from "./llm.js";
 export * from "./config.js";
 export * from "./providers/google-genai.js";
+export * from "./providers/mock.js";

packages/llm/src/providers/mock.ts

@@ -0,0 +1,24 @@
+import { z } from "zod";
+import { ILLMProvider, LLMRequest, LLMResponse } from "../llm.js";
+
+export class MockLLMProvider implements ILLMProvider {
+  providerName = "mock";
+  private callCount = 0;
+
+  constructor(private responses: unknown[]) {}
+
+  async generateStructuredResponse<T extends z.ZodTypeAny>(
+    request: LLMRequest<T>,
+  ): Promise<LLMResponse<z.infer<T>>> {
+    const next = this.responses[this.callCount++];
+    if (next === undefined) {
+      return { success: false, error: "Mock responses exhausted" };
+    }
+    try {
+      const parsed = request.schema.parse(next);
+      return { success: true, data: parsed };
+    } catch (e) {
+      return { success: false, error: e instanceof Error ? e.message : String(e) };
+    }
+  }
+}