fix: remove as-any cast in callGeminiAPI, use CONFIG.MODEL_NAME in test

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: aaronbrezel

__tests__/api.test.ts

@@ -14,6 +14,7 @@
 // ── Import after mocks ─────────────────────────────────────────
 
 import { buildGeminiPayload, callGeminiAPI } from "../src/server/api";
+import { CONFIG } from "../src/server/config";
 import type { GeminiRequest } from "../src/shared/types";
 
 // ── Helpers ────────────────────────────────────────────────────
@@ -124,6 +125,6 @@ describe("callGeminiAPI", () => {
     mockFetchResponse({ candidates: [{ content: { parts: [{ text: "ok" }] } }] });
     callGeminiAPI(baseReq);
     const url = (UrlFetchApp.fetch as jest.Mock).mock.calls[0][0];
-    expect(url).toContain("gemini-2.0-flash");
+    expect(url).toContain(CONFIG.MODEL_NAME);
   });
 });

src/server/api.ts

@@ -61,5 +61,8 @@ export function callGeminiAPI(req: GeminiRequest): string {
   const json = JSON.parse(response.getContentText()) as Record<string, unknown>;
 
   if (json.error) throw new Error((json.error as { message: string }).message);
-  return (json.candidates as any)?.[0]?.content?.parts?.[0]?.text ?? "No response.";
+  const candidates = json.candidates as
+    | Array<{ content: { parts: Array<{ text: string }> } }>
+    | undefined;
+  return candidates?.[0]?.content?.parts?.[0]?.text ?? "No response.";
 }