fix(api-key): error details not passed to response (#7692)

Co-authored-by: Alex Yang <himself65@outlook.com>

packages/better-auth/src/plugins/api-key/api-key.test.ts

@@ -3000,6 +3000,8 @@ describe("api-key", async () => {
 			const result3 = await auth.api.verifyApiKey({ body: { key: key.key } });
 			expect(result3.valid).toBe(false);
 			expect(result3.error?.code).toBe("RATE_LIMITED");
+			expect(result3.error).toHaveProperty("details");
+			expect((result3.error as any)?.details).toHaveProperty("tryAgainIn");
 		});
 
 		it("should defer remaining count updates", async () => {

packages/better-auth/src/plugins/api-key/routes/verify-api-key.ts

@@ -311,6 +311,7 @@ export function verifyApiKey({
 					return ctx.json({
 						valid: false,
 						error: {
+							...error.body,
 							message: error.body?.message,
 							code: error.body?.code as string,
 						},